Answer:
The molar mass of aspirin (C9H8O4) can be calculated as follows:
1 mol C = 12.01 g
9 mol C = 9 x 12.01 g = 108.09 g
8 mol H = 8 x 1.01 g = 8.08 g
4 mol O = 4 x 16.00 g = 64.00 g
Total molar mass of aspirin = 180.17 g/mol
To determine the number of aspirin molecules in 200 mg of aspirin, we first need to convert the mass of aspirin to moles:
200 mg aspirin x (1 g / 1000 mg) x (1 mol / 180.17 g) = 0.001110 moles aspirin
Next, we use Avogadro's number to convert moles of aspirin to molecules:
0.001110 moles aspirin x 6.022 x 10^23 molecules/mol = 6.68 x 10^20 aspirin molecules
Therefore, there are approximately 6.68 x 10^20 aspirin molecules in 200 mg of aspirin.
for lihium the enthalpy of sublimation is + 161 kj mol-¹, and the first ionisation energy is +520 kj mol-¹ and the eletron affinity of fluorine is -328 kj mol-¹ the lattice energy of fluorine is - 1047 kj mol-¹, calculate the overall enthalpy change for the reaction Li(s) + ½F2(g)---->lif(s) ΔH⁰
Answer:
The reaction can be broken down into the following steps:
1. Li(s) → Li(g) (enthalpy of sublimation)
2. Li(g) → Li⁺(g) + e⁻ (first ionization energy)
3. ½F2(g) → F(g) (½ of electron affinity of fluorine)
4. Li⁺(g) + F(g) → LiF(s) (lattice energy of LiF)
The overall enthalpy change for the reaction is:
ΔH⁰ = enthalpy change for step 1 + enthalpy change for step 2 + enthalpy change for step 3 + enthalpy change for step 4
ΔH⁰ = (+161 kJ/mol) + (+520 kJ/mol) + (½ x (-328 kJ/mol)) + (-1047 kJ/mol)
ΔH⁰ = -694 kJ/mol
Therefore, the overall enthalpy change for the reaction Li(s) + ½F2(g) → LiF(s) is -694 kJ/mol.
The chemical reaction that produces ethanol also produces what by-product?
Multiple choice question.
cross out
A)
carbon dioxide
cross out
B)
oxygen
cross out
C)
water
cross out
D)
petroleum
4Na + O2 → 2Na2O
How many moles of sodium oxide, Na2O, are produced when oxygen gas and 17.0 moles of sodium react?
When oxygen gas and 17.0 moles of sodium combine, 8.50 moles of Na2O are created.
What is mole?The unit of measurement known as a mole (mol) is used to represent the quantity of a substance. The amount of a substance that has the same number of particles (atoms, molecules, or ions) as there are in 12 grams of carbon-12 is referred to as a mole. This number, which is roughly 6.022 x 1023, is referred to as Avogadro's number.
How do you determine it?For the interaction between sodium and oxygen to form sodium oxide, the balanced chemical equation is:
4Na + O2 → 2Na2O
We can deduce from the equation that when 4 moles of sodium combine with 1 mole of oxygen, 2 moles of sodium oxide are created.
So, we must use stoichiometry to calculate how many moles of Na2O are created when 17.0 moles of Na react:
17.0 moles of Na × (1 mole of O2/ 4 moles of Na) × (2 moles of Na2O / 1 mole of O2) = 8.50 moles of Na2O
Consequently, when oxygen gas and 17.0 moles of sodium combine, 8.50 moles of Na2O are created.
To know more about mole, visit:
https://brainly.com/question/26416088
#SPJ1
Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transition from the energy level =6
to the level =1.
The wavelength οf the spectral line prοduced when an electrοn in a hydrοgen atοm undergοes the transitiοn frοm the energy level n=6 tο n=1 is apprοximately 980 nanοmeters.
What is Wavelength?Wavelength is a term used tο describe the distance between twο adjacent peaks οr trοughs οf a wave. It is usually denοted by the Greek letter lambda (λ) and is measured in units οf length, such as meters, centimeters, οr nanοmeters.
The wavelength οf the spectral line prοduced when an electrοn in a hydrοgen atοm undergοes the transitiοn frοm the energy level n=6 tο n=1 can be calculated using the Rydberg fοrmula:
1/λ = R (1/n1² - 1/n2²)
where λ is the wavelength οf the spectral line,
R is the Rydberg cοnstant (1.097 × 10⁷ m⁻¹),
n1 is the initial energy level (6 in this case), and
n2 is the final energy level (1 in this case).
1/λ = R (1/n1² - 1/n2²)
= (1.097 × 10⁷ m⁻¹) (1/6² - 1/1²)
= (1.097 × 10⁷ m⁻¹) (1/36 - 1/1)
= (1.097 × 10⁷ m⁻¹) (1/36 - 1)
= (1.097 × 10⁷ m⁻¹) (-35/36)
= -1.02 × 10⁶ m⁻¹
Taking the reciprοcal οf bοth sides οf the equatiοn, we get:
λ = -1/(1.02 × 10⁶ m⁻¹)
= 9.80 × 10^-7 m
Finally, cοnverting this tο nanοmeters, we get:
λ = 9.80 × 10⁻⁷ m × (1 nm / 10⁻⁹ m)
= 980 nm
Therefοre, the wavelength οf the spectral line prοduced when an electrοn in a hydrοgen atοm undergοes the transitiοn frοm the energy level n=6 tο n=1 is apprοximately 980 nanοmeters.
Learn more about Wavelength from given link
brainly.com/question/10750459
#SPJ1
Explain the role of gravity in the formation of galaxies.
Answer:
Gravity is the long-range force that can pull entities with mass together over great distances to form galaxies, stars and planetary material. These objects are all the consequence of atoms and ions being first clustered into huge clouds of gas.
Could you guys please help me with this, I really don't have idea how to do?:(
The results of this investigation indicate that the quantity of salt dissolved in water affects how quickly an iron nail rusts.
What are the steps of the investigation of the rusting of nails?The steps of the investigation of the rusting of nails are as follows:
Introduction:
Rusting is a common process in which iron reacts with oxygen and water in the presence of an electrolyte to form hydrated iron (III) oxide, commonly known as rust. In this investigation, we will explore how the amount of salt dissolved in water affects the rusting reaction of an iron nail.
Materials:
Iron nail
Water
Salt
3 small beakers
Stopwatch
Paper towels
Procedure:
Fill each beaker with 50 ml of water.
Dissolve different amounts of salt in each beaker as follows:
Beaker 1: 0 grams of salt
Beaker 2: 5 grams of salt
Beaker 3: 10 grams of salt
Place an iron nail in each beaker.
Record the time and observe the nails every hour for 6 hours.
Record your observations and take photos of the nails at the end of each hour.
At the end of the experiment, dry the nails with paper towels and compare their appearance.
Observations:
Beaker 1: No visible rust on the nail throughout the experiment.
Beaker 2: A small amount of rust appeared on the nail after 2 hours. The rust increased over time and covered about 25% of the nail surface after 6 hours.
Beaker 3: A significant amount of rust appeared on the nail after 1 hour. The rust increased rapidly and covered about 80% of the nail surface after 6 hours.
Conclusion:
The results of this investigation suggest that the rusting reaction of an iron nail depends on the amount of salt dissolved in water. When no salt was added to the water, no visible rust appeared on the nail. However, when salt was added, rust appeared on the nail. The amount of rust increased with the amount of salt added, indicating that the rusting reaction is accelerated in the presence of an electrolyte such as salt. This is because the presence of ions in the solution helps to conduct electricity, which facilitates the transfer of electrons between the iron and oxygen molecules, thus accelerating the rusting process.
Learn more about rusting of iron at: https://brainly.com/question/29136931
#SPJ1
Suppose the following two reactions have yields of 82% and 65%, respectively. How many
grams of CH are needed to form 112 g of CH₂Cl₂? Assume there is an excess of Cl₂.
a. CH + Cl₂
→CH,CI + HCI
82% yield
b. CH,CI+ Cl₂CH₂Cl₂ + HCI
-
65% yield
63.4 g of CH is needed to form 112 g of CH₂Cl₂.
What is the purpose of assuming excess Cl₂ in the given reaction?Excess Cl₂ is assumed in the given reaction to ensure that all the CH available is consumed completely in the reaction, and there is no Cl₂ left over.
Let's assume x grams of CH is needed to form 112 g of CH₂Cl₂.
From the balanced equation of the second reaction, we can say that one mole of CH produces one mole of CH₂Cl₂.
Molar mass of CH₂Cl₂ = 12.01 + 2(1.01) + 2(35.45) = 84.93 g/mol
Number of moles of CH₂Cl₂ = 112 g / 84.93 g/mol = 1.318 mol
Since 65% yield is given for the second reaction, the actual amount of CH,CI produced will be 0.65 mol.
From the balanced equation of the first reaction, we can say that one mole of CH reacts with one mole of Cl₂ to produce one mole of CH,CI.
Since 82% yield is given for the first reaction, the actual amount of CH needed will be 0.65 / 0.82 = 0.793 mol.
Now, we can calculate the mass of CH needed as follows:
Mass of CH needed = 0.793 mol x 16.04 g/mol = 12.71 g
Learn more about "balanced equation" here:
https://brainly.com/question/7181548
#SPJ1
in the hydrolysis of pcl3 what mass of HCl can be produced from 15.0g of pcl3the equation for the reaction is Pcl3 +3H2O-- 3HCL + H3PO3
For the reaction, 2 N2O5(g) → 4 NO2(g) + O2(g), the rate of formation of NO2(g)
is 4.0 x 10-3 mol L-1s-1.
(a) Calculate the rate of disappearance of N2O5(g)
(b) Calculate the rate of appearance of O2(g).
The rate of disappearance of N2O5 is -2.0 x [tex]10^{-3}[/tex] mol[tex]L^{-1}[/tex] [tex]s^{-1}[/tex]. The rate of appearance of O2 is 1.0 x [tex]10^{-3}[/tex] mol [tex]L^{-1} s^{-1}[/tex].
How is the rate of disappearance of N2O5(g) calculated?The stoichiometric coefficient of N2O5 in the balanced equation is 2, whereas the stoichiometric coefficient of NO2 is 4. As a result, the rate of N2O5 dissolution is proportional to the rate of NO2 production. As a result, the rate at which N2O5(g) dissipates is:
N2O5(g) rate of dissolution = - (1/2) (4.0 x [tex]10^{-3} mol L^{-1} s^{-1}[/tex]) = -2.0 x [tex]10^{-3} mol L^{-1} s^{-1}[/tex]
How do you determine the pace at which O2(g) appears?O2(g) appears at a pace that is proportionally half as fast as N2O5 vanishes (g). As a result, the rate at which O2(g) appears is:
Rate of emergence of O2(g) = (1/2) × (2.0 × [tex]10^{-3} mol L^{-1} s^{-1}[/tex]) = 1.0 × [tex]10^{-3} mol L^{-1} s^{-1}[/tex]
To learn more about rate of a reaction visit:
brainly.com/question/8592296
#SPJ1
Which slow carbon reservoir is being turned into a fast carbon reservoir by humans?
Which of these is an example of an agricultural use for radiation?
A. making heavy isotopes to find new elements.
B. irradiating wheat to kill fungus.
C. diagnostic procedures that image inside the body, such as a PET scan.
D. locating leaks in a water line in a building.
Option B. irradiating wheat to kill fungus is an example of agricultural use for radiation.
What is the relative significance of agricultural use for radiation?The relative significance of agricultural use for radiation is based on the fact that radiation is a physic mutagenic agent and therefore it can be sued to produce mutations in undesired organisms in order to kill them.
Therefore, with this data, we can see that the relative significance of agricultural use for radiation is based on the generation of triggered mutations in undesired organisms such as plagues.
Learn more about the use of radiation here:
https://brainly.com/question/1333944
#SPJ1
If you want to seprate the liquid solvent from solution and not keep it what separation method can you use?
You can use the method of distillation to separate the liquid solvent from the solution. In distillation, the solution is heated to its boiling point, and the solvent evaporates into a gas. The gas is then condensed back into a liquid and collected in a separate container, leaving behind the solute. This method is useful when you want to recover the solvent for reuse or dispose of it properly.
The industrial synthesis of sulphuric acid proceeds first with the reaction between gaseous sulphur dioxide and oxygen:
2SO2(g)+O2(g)⇌2SO3(g)
A mixture of SO2 and O2 was maintained at 800 K until the system reached equilibrium. The equilibrium mixture contained:
5.0×10−2 M SO3,
3.5×10−3 M O2, and
3.0×10−3 M SO2.
Write equilibrium constant expression and calculate Kc at this temperature.
The equilibrium constant (Kc) at 800 K is 4.86 × 10³
What is the equilibrium constant?The equilibrium constant expression for the given reaction is:
Kc = [SO3]^2 / ([SO2]^2 [O2])
where;
[SO3], [SO2], and [O2] represent the equilibrium concentrations of sulphur trioxide, sulphur dioxide, and oxygen, respectively.Substituting the given equilibrium concentrations in the expression, we get:
Kc = (5.0×10^-2)^2 / ((3.0×10^-3)^2 × 3.5×10^-3)
Kc = 4.86 × 10³ (rounded to 3 significant figures)
Therefore, the equilibrium constant (Kc) at 800 K is 4.86 × 10³
Learn more about equilibrium constant here: https://brainly.com/question/19340344
#SPJ1
[tex] \:\:\:\:\:\:\star[/tex]The equilibrium constant, Kc can be deduced for a reversible reaction by using the following expression:
[tex] \:\:\:\:\:\:\star\longrightarrow\sf \underline{Kc = \dfrac{\bigg[Products\bigg ]}{\bigg[Reactants \bigg]}}\\[/tex]
For a reaction [tex]\boxed{\sf xP+yQ=zPQ}[/tex] the equilibrium constant Kc is defined as [tex]\sf[PQ]^z/[P]^x[Q]^y[/tex].Where brackets denote reagent concentrations (in molarity) of each substance that must be given in order to compute the equilibrium constant Kc and each concentration term is raised to the power of its coefficient in the balanced chemical equation.Now for solving this problem we may write the equilibrium expression for the reaction system.
[tex] \:\star\:\sf2\:SO_2\:(g)\:+O_2\:(g)\:⇌2\:SO_3\:(g)\:\\[/tex]
The equilibrium constant expression for the given reaction is:
[tex] \:\:\:\:\:\:\star\longrightarrow \sf \underline{Kc = \dfrac{\bigg[SO_3\bigg]^2 }{ \bigg[SO_2\bigg]^2\:\bigg [O_2\bigg]}....Eq}\\[/tex]
As per question, following concentrations are present in the system is given -
[tex] \sf{[SO_3] = 5.0×10^{−2}\:M}[/tex][tex]\sf{ [O_2] =3.5×10^{−3 }\:M}[/tex][tex] \sf{[SO_2]=3.0×10^{−3}\: M}[/tex]Now that, we have all the required molar equilibrium concentrations, so we can substitute the molar equilibrium concentrations into the equation and calculate the value of Kc:-[tex] \:\:\:\:\:\:\star\longrightarrow \sf \underline{ Kc = \dfrac{\bigg[SO_3\bigg]^2 }{ \bigg[SO_2\bigg]^2\:\bigg [O_2\bigg]}}\\[/tex]
[tex] \:\:\:\:\:\:\longrightarrow \sf Kc = \dfrac{\bigg[5\times 10^{-2}\bigg]^2 }{ \bigg[3\times10^{-3}\bigg]^2\:\bigg [3\times10^{-3}\bigg]}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf Kc = \dfrac{25\times 10^{-4}}{9\times 10^{-6}\times3.5\times 10^{-3}}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf Kc=\dfrac{25}{9\times3.5}\times 10^{-4}\times10^{3}\times10^{6}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf Kc=\dfrac{25}{31.5}\times 10^{-4+3+6}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf Kc=\cancel{\dfrac{25}{31.5}}\times 10^{5}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf Kc= 0.793650......\times 10^{5}\\[/tex]
[tex] \:\:\:\:\:\:\:\:\:\:\:\longrightarrow \sf \underline{Kc= 7.9365\times 10^{4}}\\[/tex]
Therefore,the equilibrium constant (Kc) at 800 K is [tex]\bf\underline{ 7.9365\times 10^{4}.}\\[/tex]
Does butan-2-one or butan-2-ol have higher boiling point?
MUST HAVE GOOD EXPLANATION 30 POINTS
Butan-2-one has a higher boiling point than butan-2-ol.
Why does butan-2-one have a higher boiling point than butan-2-ol?Butan-2-one has a higher boiling point than butan-2-ol because it has a higher molecular weight and more polar carbonyl group, which results in stronger intermolecular forces between molecules.
What are some potential applications of butan-2-one and butan-2-ol?Butan-2-one (also known as methyl ethyl ketone) is commonly used as a solvent in various industrial applications, such as in the production of plastics, textiles, and adhesives. Butan-2-ol (also known as sec-butanol) is also used as a solvent, as well as a chemical intermediate in the production of other chemicals such as butyl acetate and glycol ethers. Both compounds are also used as flavor and fragrance ingredients in food and cosmetic products.
Learn more about "Butan-2-one" here:
https://brainly.com/question/2142051
#SPJ1
How many liters of NaN3 react to produce 14.7 Liters of Na2O
Answer:
he balanced chemical equation for the reaction between NaN3 and Na2O is:
2 NaN3(s) → 2 Na(s) + 3 N2(g)
According to the stoichiometry of this equation, 2 moles of NaN3 will produce 2 moles of Na, which in turn will react with 3 moles of N2. Therefore, the volume of N2 gas produced is proportional to the volume of NaN3 used.
To find the volume of NaN3 required to produce 14.7 liters of N2, we need to use the ideal gas law:
PV = nRT
where P is the pressure of the gas, V is the volume of the gas, n is the number of moles of the gas, R is the gas constant, and T is the temperature of the gas.
Assuming standard temperature and pressure (STP), which is 0°C and 1 atmosphere, we can simplify the equation to:
V = n/22.4
where V is the volume of the gas in liters and n is the number of moles of the gas.
We can use this equation to convert the volume of N2 to moles:
n = PV/RT = (1 atm)(14.7 L)/(0.08206 L·atm/mol·K)(273 K) = 0.608 mol
According to the stoichiometry of the balanced equation, 2 moles of NaN3 will produce 0.608 mol of N2. Therefore, the number of moles of NaN3 required is:
n(NaN3) = 2 × n(N2) = 2 × 0.608 mol = 1.216 mol
Finally, we can use the molar volume of a gas at STP to convert the number of moles to volume:
V(NaN3) = n(NaN3)/22.4 = 1.216 mol/22.4 L/mol = 0.054 L
Therefore, 0.054 liters of NaN3 are required to produce 14.7 liters of Na2O.
ill mark you as a brainlistttt
The most common source of copper ( Cu ) is the mineral chalcopyrite ( CuFeS2 ). How many kilograms of chalcopyrite must be mined to obtain 400. g of pure Cu ?
Express your answer to three significant figures and include the appropriate units.
Answer:
3.29 kg of chalcopyrite must be mined to obtain 400 g of pure Cu.
Explanation:
The molar mass of Cu is 63.55 g/mol. To determine the amount of Cu present in 1 mole of chalcopyrite, we need to calculate the molar mass of CuFeS2:
Cu: 1 atom x 63.55 g/mol = 63.55 g/mol
Fe: 1 atom x 55.85 g/mol = 55.85 g/mol
S: 2 atoms x 32.06 g/mol = 64.12 g/mol
Molar mass of CuFeS2 = 63.55 + 55.85 + 64.12 = 183.52 g/mol
Therefore, 1 mole of chalcopyrite contains 63.55 g/mol / 183.52 g/mol = 0.3466 moles of Cu.
To obtain 400 g of pure Cu, we need to convert the mass of Cu to moles:
400 g / 63.55 g/mol = 6.2978 moles of Cu
Finally, we can use the mole ratio between Cu and chalcopyrite to determine the amount of chalcopyrite needed:
1 mole Cu / 0.3466 moles CuFeS2 = 2.885 moles CuFeS2
6.2978 moles Cu x (1 mole CuFeS2 / 2.885 moles Cu) x (183.52 g/mol CuFeS2 / 1000 g) = 3.29 kg of chalcopyrite
Therefore, approximately 3.29 kg of chalcopyrite must be mined to obtain 400 g of pure Cu.
We know that the specific heat of water c = 1 calorie/g/oC For water, the latent heat of evaporation is 540 calories per gram, and latent heat of melting (or freezing) is 80 calories per gram. Answer the following questions Question 1: How much heat would be required to heat 1 gram of pure liquid water from 10oC to 20oC?
Answer:
10 calories of heat would be required to heat 1 gram of pure liquid water from 10°C to 20°C.
Explanation:
To calculate the heat required to heat 1 gram of pure liquid water from 10°C to 20°C, we need to use the specific heat formula:
Q = m * c * ΔT
where Q is the heat required, m is the mass of the substance, c is the specific heat of the substance, and ΔT is the change in temperature.
In this case, m = 1 gram, c = 1 calorie/g/°C, and ΔT = (20°C - 10°C) = 10°C. Substituting these values into the formula, we get:
Q = 1 gram * 1 calorie/g/°C * 10°C
Q = 10 calories
Therefore, 10 calories of heat would be required to heat 1 gram of pure liquid water from 10°C to 20°C.
What is the coefficient for hydrogen in the balanced equation for the reaction of solid molybdenum(IV) oxide with gaseous hydrogen to form solid molybdenum and liquid water?
A.1
B.2
C.6
D.4
The reaction's balanced chemical equation is MoO2(s) + 4H2(g) Mo(s) + 2H2O. (l). Hydrogen has a coefficient of 4.
What is the balanced equation for the reaction that takes place during the Haber process to produce ammonia?The Haber process produces ammonia from nitrogen and hydrogen: NH3 = N2(g) + 3H2(g) (g) The reaction moving ahead is exothermic.
What does the balanced chemical equation of the Haber process look like?A method used in industry to make ammonia by reacting hydrogen and nitrogen: N2+3H2 ⇌ 2NH3 Low temperature is preferred for a high ammonia production since the reaction is reversible and exothermic (see Le Chatelier's principle).
To know more about hydrogen visit:-
https://brainly.com/question/28937951
#SPJ1
A solution contains an unknown amount of dissolved calcium. Addition of 0.679 mol of K3PO4 causes complete precipitation of all of the calcium.
How many moles of calcium were dissolved in the solution?
What mass of calcium was dissolved in the solution?
Answer:
The balanced chemical equation for the reaction between calcium ions (Ca2+) and phosphate ions (PO43-) is:
3Ca2+ + 2PO43- → Ca3(PO4)2
According to the equation, 3 moles of calcium ions react with 2 moles of phosphate ions to form 1 mole of calcium phosphate.
If 0.679 mol of phosphate ions are added and all the calcium ions are removed from the solution, then the amount of calcium ions originally present must be (3/2) * 0.679 = 1.0185 moles.
To calculate the mass of calcium dissolved in the solution, we need to know the molar mass of calcium. The molar mass of calcium is 40.08 g/mol.
Therefore, the mass of calcium dissolved in the solution is:
1.0185 moles * 40.08 g/mol = 40.77 g
A cup contains 185 g of coffee at 99.4 °C. Suppose 62.7 g of ice is added to the coffee. What is the temperature of the coffee after all of the ice melts? The enthalpy of fusion of water can be found in this table. Assume the specific heat capacity of the coffee is the same as water.
final=°C
Complete and balance each combustion reaction.
1.Al(s)+O2(g)→
2.C9H20(l)+O2(g)→
3.C8H18O(l)+O2 (g)→
4.SiC(s)+O2(g)→
The complete and balanced equation for each reaction would be as follows:
4Al(s) + 3O2(g) → 2Al2O3(s)C9H20(l) + 14O2(g) → 9CO2(g) + 10H2O(g)C8H18O(l) + 25O2(g) → 16CO2(g) + 18H2O(g)SiC(s) + 2O2(g) → SiO2(s) + CO2(g)Balancing chemical reactionsTo balance a chemical equation, you need to ensure that the number of atoms of each element is the same on both the reactant and product sides.
This is done by adjusting the coefficients (numbers in front of the chemical formulas) until the equation is balanced. The coefficients must be the smallest whole numbers possible, and it may be necessary to add additional reactants or products to balance the equation.
Thus, the complete and balanced chemical equations for the reactions would be:
4Al(s) + 3O2(g) → 2Al2O3(s)C9H20(l) + 14O2(g) → 9CO2(g) + 10H2O(g)C8H18O(l) + 25O2(g) → 16CO2(g) + 18H2O(g)SiC(s) + 2O2(g) → SiO2(s) + CO2(g)More on balancing chemical equations can be found here: https://brainly.com/question/28294176
#SPJ1
Based on the first table, can someone answer these questions in the second image?
a).017 moles of copper will react with 4 x 0.017 = 0.068 moles of HNO3.
B) As excess HNO3 is 0.019mol, so for this reaction 0.019 mol/2 = 0.0095 mol of Na2CO3 will be required.
What uses does copper have?Due to its ductility and excellent conductivity, copper is primarily used in electrical generators, home and auto wiring, and the wires in electronics like radios, TVs, computers, lights, and motors.
Mass of copper = 1.07 g
Molar mass of copper = 63.55 g / mol
Moles of copper = mass/ molar mass = 1.07g/ 63.55g/mol = 0.017 mol
Vol of HNO3 = 5.5 ml
Concentration of HNO3 = 15.8 M
Moles of HNO3 = vol x concentration = (5.5/1000)L x 15.8 mol/L = 0.087 mol
(Since concentration is given in moles/L the volume also needs to be converted to liters. 5.5ml = 5.5/1000 L)
Based on the balanced chemical equation, 4 moles of HNO3 will react with 1 mole of copper to give 1 mole of copper nitrate.
So 0.017 moles of copper will react with 4 x 0.017 = 0.068 moles of HNO3.
Excess moles of HNO3 = moles of HNO3 added - moles of HNO3 reacted = 0.087mol- 0.068mol = 0.019 mol
On addition of Na2CO3 following reactions will occur
2) 2HNO3 + Na2CO3 ----------> 2NaNO3 + CO2 + H2O
This is the reaction that will take place between sodium carbonate and excess nitric acid. 2 moles of HNO3 will react with 1 mole of Na2CO3. As excess HNO3 is 0.019mol, so for this reaction 0.019 mol/2 = 0.0095 mol of Na2CO3 will be required.
Learn more about copper
https://brainly.com/question/13677872
#SPJ1
Question 4:
1. Suppose a 70-kg individual drinks 2 L/day of water containing 0.1
mg/L of 1,1-dichloroethylene for 20 years.
(a) Find the hazard quotient for this exposure.
(b) Find the cancer risk.
(c) If the individual drinks this water for 30 years instead of just 20,
recompute the hazard quotient and the cancer risk.
(a) The hazard quotient is:
HQ = Intake / RfD = 0.0002 mg/day / 0.02 mg/kg/day = 0.01
(b) The cancer risk is 1 in 10,000.
(c) The cancer risk is 1 in 1,000.
What is Hazard quotient?Hazard quotient (HQ) is a measure used in risk assessment to evaluate the potential health risk posed by exposure to a chemical or other hazard. It is calculated as the ratio of the dose or exposure level of the chemical to a reference dose (RfD) or reference concentration (RfC) established by regulatory agencies or scientific bodies as a safe level of exposure. If the hazard quotient is greater than 1, it suggests that the level of exposure is of potential concern and additional risk assessment may be needed.
(a) The hazard quotient (HQ) is calculated as the daily intake of a chemical divided by its reference dose (RfD). The RfD for 1,1-dichloroethylene is 0.02 mg/kg/day.
The daily intake of 1,1-dichloroethylene can be calculated as:
Intake = concentration × ingestion rate × body weight
Intake = 0.1 μg/L × 2 L/day × 70 kg = 14 μg/day = 0.0002 mg/day
The hazard quotient is:
HQ = Intake / RfD = 0.0002 mg/day / 0.02 mg/kg/day = 0.01
(b) The cancer risk from exposure to 1,1-dichloroethylene can be estimated using the unit risk factor (URF) for this chemical, which is 0.5 per mg/kg/day. The cancer risk is calculated as:
Risk = Intake × URF = 0.0002 mg/day × 0.5 per mg/kg/day = 0.0001
Therefore, the cancer risk is 1 in 10,000.
(c) If the individual drinks this water for 30 years, the total exposure would be:
Exposure = Intake × 365 days/year × 30 years = 2.19 mg
The new hazard quotient is:
HQ = Exposure / (RfD × body weight) = 2.19 mg / (0.02 mg/kg/day × 70 kg) = 1.57
The new cancer risk is:
Risk = Exposure × URF = 2.19 mg × 0.5 per mg/kg/day = 1.10
Therefore, the cancer risk is 1 in 1,000.
To know more about cancer, visit:
https://brainly.com/question/8590464
#SPJ1
What volume of 0.95 M HCl in mL is required to titrate 1.651 g of Na2CO3 to the equivalence point?
Na2CO3 (aq) + 2HCl (aq) ---> H2O (l) + CO2 (g) + 2 NaCl (aq)
We need 32.8 mL of 0.95 M HCl to titrate 1.651 g of Na2CO3 to the equivalence point.
What is titration ?
Titration is a laboratory technique used to determine the concentration of an unknown solution (the analyte) by reacting it with a solution of known concentration (the titrant). In a typical titration, a measured volume of the titrant solution is slowly added to the analyte solution until the reaction is complete, as indicated by a color change or other observable signal. The volume of titrant required to reach the end-point is used to calculate the concentration of the analyte solution.
Titration is commonly used in analytical chemistry to determine the concentration of acids, bases, and other substances in a variety of samples. It is a precise and accurate method for determining the concentration of a solution, and is widely used in industry, research, and education.
From the balanced chemical equation, we can see that 1 mole of Na2CO3 reacts with 2 moles of HCl to produce 1 mole of CO2.
First, we need to calculate the number of moles of Na2CO3 in 1.651 g:
moles of Na2CO3 = mass / molar mass
molar mass of Na2CO3 = 2(22.99 g/mol) + 12.01 g/mol + 3(16.00 g/mol) = 105.99 g/mol
moles of Na2CO3 = 1.651 g / 105.99 g/mol = 0.0156 mol
Since two moles of HCl are required to react with one mole of Na2CO3, we need 2 x 0.0156 = 0.0312 moles of HCl to reach the equivalence point.
Now, we can use the molarity of the HCl solution to calculate the required volume:
moles of HCl = Molarity x volume (in liters)
0.0312 mol = 0.95 mol/L x volume (in liters)
volume (in liters) = 0.0312 mol / 0.95 mol/L = 0.0328 L
Finally, we can convert the volume to milliliters:
volume (in mL) = 0.0328 L x 1000 mL/L = 32.8 mL
Therefore, we need 32.8 mL of 0.95 M HCl to titrate 1.651 g of Na2CO3 to the equivalence point.
To know more about Titration visit :-
https://brainly.com/question/186765
#SPJ9
An unknown element X has the following isotopes: ⁵²X (90.00% abundant, atomic mass = 52.04 amu), ⁴⁹X (8.00% abundant, atomic mass = 48.99 amu), and ⁵⁰X (2.00% abundant, atomic mass = 50.09 amu). What is the average atomic mass of X in amu?
An unknown element X has the following isotopes: ⁵²X (90.00% abundant, atomic mass = 52.04 amu), ⁴⁹X (8.00% abundant, atomic mass = 48.99 amu), and ⁵⁰X (2.00% abundant, atomic mass = 50.09 amu). The average atomic mass of X is 51.72 amu.
What are isotopes?Isotopes are variations of chemical elements that have a varied number of neutrons but the same number of protons and electrons. In other words, isotopes are different forms of the same element that have different amounts of nucleons (the sum of protons and neutrons) because of variations in the total number of neutrons in each of their individual nuclei.
For instance, the carbon isotopes carbon-14, carbon-13, and carbon-12 all exist. A total of 8 neutrons are present in carbon-14, 7 neutrons are present in carbon-13, and 6 neutrons are present in carbon-12.
Using the formula:
Average atomic mass=∑[tex]\frac{abundance}{100}[/tex]× Atomic mass
Substituting the values,
Average atomic mass = 51.72 amu
To know more about Neutrons, visit:
https://brainly.com/question/28992636
#SPJ9
What is barium bromide and chromium (II) sulfate net ionic equation. With the solubility signs.
Answer:
NET equation: 2Br^- (aq) + Cr2+ (aq) → CrBr2 (aq)
The solubility signs for each compound are:
Barium bromide (BaBr2): (aq) - aqueous (soluble)
Chromium (II) sulfate (CrSO4): (aq) - aqueous (slightly soluble)
Barium sulfate (BaSO4): (s) - solid (insoluble)
Chromium (II) bromide (CrBr2): (aq) - aqueous (soluble)
Explanation:
Barium bromide and chromium (II) sulfate are both ionic compounds that can dissociate into their constituent ions in aqueous solutions. To write the net ionic equation for the reaction between barium bromide and chromium (II) sulfate, we first need to determine the state of the reactants and products (whether they are soluble or insoluble in water) using solubility rules.
Barium bromide (BaBr2) is soluble in water, while chromium (II) sulfate (CrSO4) is slightly soluble. When the two are mixed in water, a double displacement reaction takes place, producing barium sulfate (BaSO4) and chromium (II) bromide (CrBr2) as the products:
BaBr2 (aq) + CrSO4 (aq) → BaSO4 (s) + CrBr2 (aq)
To write the net ionic equation, we need to eliminate any spectator ions that do not participate in the reaction. In this case, the barium and sulfate ions are spectator ions, as they appear unchanged on both sides of the equation. The net ionic equation is therefore:
2Br^- (aq) + Cr2+ (aq) → CrBr2 (aq)
where Br^- and Cr2+ are the ions that actually participate in the reaction.
The solubility signs for each compound are:
Barium bromide (BaBr2): (aq) - aqueous (soluble)
Chromium (II) sulfate (CrSO4): (aq) - aqueous (slightly soluble)
Barium sulfate (BaSO4): (s) - solid (insoluble)
Chromium (II) bromide (CrBr2): (aq) - aqueous (soluble)
How many moles of mg are present in 2.5 x10^25 atoms mg
The number of moles of the magnesium that is involved is 42 moles
How do we use moles to find the number of atoms?To find the number of atoms using moles, we need to use Avogadro's number, which is the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. Avogadro's number is approximately 6.022 x 10^23 particles per mole.
The formula to find the number of atoms using moles is:
Number of atoms = number of moles x Avogadro's number
We know that;
1 mole would contain 6.02 * 10^23 atoms
x moles will contain 2.5 x10^25 atoms
x = 42 moles
Learn more about moles:https://brainly.com/question/20486415
#SPJ1
What is the pH of a 1.0 L buffer made with 0.300 mol of HF (Ka = 6.8 × 10⁻⁴) and 0.200 mol of NaF to which 0.100 mol of HCl were added?
the pH of the buffer solution after adding 0.100 mol of HCl is 2.99.
how to solve this problem, we will use the Henderson-Hasselbalch equation ?
pH = pKa + log([A-]/[HA])
where pKa is the dissociation constant of the weak acid, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the weak acid.
First, we need to calculate the concentrations of HF and NaF in the buffer solution. Since we have 0.300 mol of HF and 0.200 mol of NaF in 1.0 L of solution, the concentrations are:
[HF] = 0.300 M
[NaF] = 0.200 M
Next, we need to calculate the ratio of [A-]/[HA]. Since NaF is the conjugate base of HF, we can use the stoichiometry of the acid-base reaction to find that:
[A-]/[HA] = [NaF]/[HF] = 0.200/0.300 = 0.667
Now we can plug in the values into the Henderson-Hasselbalch equation:
pH = pKa + log([A-]/[HA])
pH = -log(6.8 × 10⁻⁴) + log(0.667)
pH = 3.17 + (-0.177)
pH = 2.99
Therefore, the pH of the buffer solution after adding 0.100 mol of HCl is 2.99.
To learn more about Henderson-Hasselbalch equation follow the given link:
https://brainly.com/question/29466914
#SPJ1
The Tropic Zones:
are located near the Equator.
are the warmest temperature zones.
receive a lot of direct sunlight.
All of these choices are correct.
The warmest climate zones, the Tropic Zones are close to the Equator and receive a lot of direct sunlight.
Is the equator close to the region with tropical climate?The tropics are parts of Earth that are situated essentially in the centre of the planet. the tropics that, in terms of latitude, are situated between the Tropics of Cancer and Capricorn. The equator and portions of North America are included in the tropics.
Why are the polar regions the coldest and the tropical regions the warmest?As an illustration, hot places are typically found closer to the equator. Because the Sun shines most directly overhead at the equator, the climate is hotter there. Moreover, the North and South Poles are chilly because they receive the least direct sunlight and heat.
To know more about direct sunlight visit:-
https://brainly.com/question/19180305
#SPJ1
what is the fertilizer that they normally use to improve the soil
Answer:
Nitrogen fertilizers: These are used to promote leafy growth and overall plant development. Examples include ammonium nitrate, urea, and ammonium sulfate.
Phosphorus fertilizers: These are used to promote root development and flowering. Examples include superphosphate and triple superphosphate.
Potassium fertilizers: These are used to improve fruit quality and disease resistance. Examples include potassium chloride and potassium sulfate.
Organic fertilizers: These are derived from natural sources such as animal manure, compost, and bone meal. They provide a slow-release source of nutrients and can also improve soil structure and fertility.
Ultimately, the choice of fertilizer will depend on the specific needs of the plants and soil conditions, and it is important to use fertilizers in moderation to avoid over-fertilization and potential environmental problems.
Explanation: