Divide the number of molecules N by avogadro's constant.
Let n be the number of moles then,
[tex]n=\frac{N}{N_A}=\frac{3.3\cdot10^{24}}{6.022\cdot10^{23}}=5.48\mathrm{mol}[/tex]
Hope this helps.
What is the name of the process happening in the picture? How do you know it’s that process? Explain your answer in 2 to 3 complete sentences
________ gas is evolved in cathode during the electrolysis of water. 20 points answer fast
Answer:
hydrogen
Explanation:
In electrolysis of water, gas evolved at cathode is hydrogen
Help solve please, it’s due in less than an hour or so.
sorry i can only figure out 1 but the answer is
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124
hope you do good on your test :D
Answer and I’ll give you brainliest!
What type of reaction is this *
N2 + H2 → NH3
O synthesis
O combustion
O decomp
O single
O double
3. A gram food sample is burned completely in a calorimeter that contains 1000. of water The temperature of the water increases 23.65 degrees * C . How many Calories does the food have per gram ?
The food has 23629.64 cal
Further explanationGiven
mass = 1000 g of water
temperature increases 23.65 * C
Required
The energy of the food
Solution
Heat absorbed by water :
Q = m . c . Δt
Q = 1000 g x 4.184 J/g°C x 23.65 °C
Q = 98951.6 J
1 Joules = 0.2388 Calories
98951.6 J = 23629.64 cal
David Robinson, a professional basketball
player, is 7 ft, 1.0 in. tall. Convert his height to
centimeters
Show work please
Answer:
215.9 cm
Explanation:
1 foot= 30.5cm
30.5cm times 7 1/12=215.9cm
The given height of David is 7 ft, 1.0 inch, so in centimeters, the height will be 216.4 cm.
What is unit conversion?A conversion factor is a number that is used to multiply or divide one set of units into another. When converting to an equal value, the appropriate conversion factor must be used.
We must convert one unit to another in order to achieve accuracy and avoid measurement confusion.
We do not, for example, measure the length of a pencil in kilometers. In this case, one must convert kilometers (km) to centimeters (cm) (cm).
To convert feet to centimeters, multiply the given foot length by 30.48 cm.
So,
Height in cm will be = 7.1 x 30.48
Height in cm = 216.4cm
Thus, the height of David in centimeters is 216.4 cm.
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what kind of crystalline solid is graphite?
Answer:
Covalent-network (also called atomic) solids—Made up of atoms connected by covalent bonds; the intermolecular forces are covalent bonds as well. Characterized as being very hard with very high melting points and being poor conductors. Examples of this type of solid are diamond and graphite, and the fullerenes.
I hope it's helpful!
Answer:
network solid
Explanation:
Help ASAP please
Which statement best describes the reaction pathway graph for an exothermic reaction but not an endothermic reaction?
It has a hill in the middle that is the highest point.
It has a valley in the middle that is its lowest point.
The reactants are higher in energy than the products.
The products are higher in energy than the reactants.
Answer: C ) The reactants are higher in energy than the products
Explanation:
The enthalpy that is a state variable that identifies the content of heat. Then the change of enthalpy for the exothermic reactions is negative, meaning that the energy of the products is lower than the energy of the reactants.
20 g of Allg is dissolved in water to produce a solution with a concentration of 2.007M. What is the volume of this solution in milliliters?
Answer:
369 ml
Explanation:
Mass of Aluminium (Al) = 20 g
Molar concentration = 2.007M
Molar concentration = Number of moles / Volume
The relationship between mass and number of moles;
Number of moles = Mass / Molar mass
Number of moles = 20 / 27 = 0.741 mol
2.007 = 0.741 / Volume
Volume = 0.741 / 2.007 = 0.369 L
converting to millilitres by multiplying by 1000
Volume = 0.369 * 1000 = 369 ml
Convert 77.2 grams of CH4 to molecules.
Answer:
сфоткай отправь. я не магу зделать
According to the concept of Avogadro's number, there are 29.056×10²³ molecules in 77.2 g of methane.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
In the given example, number of moles=77.2/16=4.825 moles
If 1 mole has 6.023×10²³ molecules , then 4.825 moles will have 4.825×6.023×10²³ /1=29.056×10²³ molecules .
Thus, there are 29.056×10²³ molecules in 77.2 g of methane.
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6. Describe nuclear fusion reactions as they
occur in the sun.
Answer:
i wish i know
Explanation:
i wish i know
Pls answer this two ASAP PLSSSSSSSS
Answer:
1. aa
2. They have similar DNA
Explanation:
1. According to the question 1, wrinkled seeds (A) are dominant over round seeds (a) in pea plants. This means that, based on the law of dominance proposed by Mendel, wrinkled seeds will be expressed over round seeds in a heterozygous state (Aa).
However, since the round seed phenotype is a recessive trait, it will only be expressed when the alleles for round seeds (a) are the same in the gene i.e. aa genotype.
2. Based on the information in question 2, Ricky, who is working on a family tree for his school project, realizes that his close relatives all look similar in the pictures he collected. This is possible because of the SIMILARITY OF THEIR DNA (genetic material). Note that, relatives are connected by the genes that are inherited from one another, hence, they possess a similar DNA, which is the most valid reason for the resemblance.
PLEASE HELP!!!! SCIENCE PROBLEM
indicator, hope this helps :
Answer:
B
Explanation:
Because that's what is being changed into a different color.
How many liters of N2 gas are in 2.4 moles at STP?
Answer:
any gas takes up 22.4L per mole so 2.4*22.4=53.76
Explanation:
In 2.4 moles at STP, 53.79 litres of N2 gas are present.
What are moles?Moles are defined as the amount of substance of a system that contain the same number of entities as the number of atoms in 12g of carbon 12.
What is STP?STP is defined as the standard temperature and pressure. At STP, as system has s temperature of zero degree centigrade or 273 Kelvin and the pressure is 1 atm.
PV= nRT
P= 1 atm
V= ?
n= 2.4 moles
R= 0.0821 L atm /K/mol
1 x V = 2.4 x 0.0821 x 273
V = 53.79 litres
Hence, 53.79 litres of N2 gas is present in 2.4 moles at STP.
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A first order reaction has a rate constant of 0.924 at 25 oC. Given that the activation energy is 89.8 kJ/mol, calculate the rate constant at 33.3 oC.
Answer:
[tex]k_2=2.46[/tex]
Explanation:
Hello!
In this case, according to the Arrhenius equation for variable temperature:
[tex]ln(\frac{k_2}{k_1} )=-\frac{Ea}{R}(\frac{1}{T_2} -\frac{1}{T_1} )[/tex]
Given the temperatures to be computed in kelvins and the activation energy, we obtain:
[tex]ln(\frac{k_2}{0.924} )=-\frac{89800J/mol}{8.314J/(mol*K)}(\frac{1}{306.45K} -\frac{1}{298.15K} )\\\\ln(\frac{k_2}{0.924} )=0.981\\\\k_2=0.924*exp(0.981)\\\\k_2=2.46[/tex]
Best regards!
Determine the density (in g/mL) of a substance with a mass of 105 g and a volume of 17.6 mL.
Answer:
Density, d = 5.96 g/mL
Explanation:
Given that,
Mass, m = 105 g
Volume, V = 17.6 mL
We need to find the density of the substance. So,
[tex]d=\dfrac{m}{V}\\\\d=\dfrac{105\ g}{17.6\ mL}\\\\d=5.96\ g/mL[/tex]
So, the density of the substance is 5.96 g/mL.
How many atoms are in 2.12 mole of propane
Answer:
More exactly this number is 6.02 x 1023 10 2 3 .
2. What is the final temperature when a 32.0 g piece of diamond at 33.5°C is heated with 360 J of energy?
(Cp = 0.509
Answer:
55.6 °C
Explanation:
From the question given above, the following data were obtained:
Mass (M) of diamond = 32.0 g
Initial temperature (T₁) = 33.5°C
Heat (Q) required = 360 J
Specific heat capacity (C) of diamond = 0.509 J/gºC
Final temperature (T₂) =?
Next, we shall determine the change in temperature. This can be obtained as follow:
The final temperature can be obtained as follow:
Mass (M) of diamond = 32.0 g
Heat (Q) required = 360 J
Specific heat capacity (C) of diamond = 0.509 J/gºC
Change in temperature (ΔT ) =?
Q = MCΔT
360 = 32 × 0.509 × ΔT
360 = 16.288 × ΔT
Divide both side by 16.288
ΔT = 360 / 16.288
ΔT = 22.1 °C
Finally, we shall determine the final temperature. This can be obtained as follow:
Initial temperature (T₁) = 33.5°C
Change in temperature (ΔT ) = 22.1 °C
Final temperature (T₂) =?
ΔT = T₂ – T₁
22.1 = T₂ – 33.5
Collect like terms
22.1 + 33.5 = T₂
T₂ = 55.6 °C
Therefore, the final temperature is 55.6 °C.
what Li(s) + O2(g) -> Li2O(s) balanced is
Answer:
4 1 2Explanation:
4 Li(s) + 1 O2(g) -> 2 Li2O(s)
To calculate the atoms of an element in a given molecule, we need to multiply stoichiometry by the number that is written on the foot of that element. Therefore, the balanced equation is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s).
What is Balanced equation?Balanced equation is the one in which the total number of atoms of a species on reactant side is equal to the total number of atoms on product side. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, displacement reaction.
The other characteristic of balanced reaction is that physical state should be written with each compound or molecule on reactant and product side. Physical state should be written in brackets. s means solid, l means liquid, g means gas. The balanced equation for the given reaction is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s)
Therefore, the balanced equation is 4 Li(s) + 1 O[tex]_2[/tex](g) [tex]\rightarrow[/tex] 2 Li[tex]_2[/tex]O(s).
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Use the periodic table to select the element that best fits each of the following descriptions.
Noble gas:
O oxygen
O chlorine
Okrypton
Answer:
Krypton
Explanation:
Which energy resource causes the greatest waste disposal concerns?
solar power
nuclear
coal
geothermal power
(1) Solution A and B are separated by a membrane that is permeable to Mg2 and impermeable to Cl-. Solution A contains 0.1 mM MgCl2, solution B contains 100 mM MgCl2. Mg2 will be at electrochemical equilibrium when solution A is around ____________ mV. 180 mV - 180 mV 90 mV - 90 mV 60 mV - 60 mV
Answer:
90 mV
Explanation:
Faraday constant, F = 96487
Gas constant, R = 8.314
Number of mole of electron transferred, Z = 2
MgCl in solution A, = 0.1 mm
MgCl in solution A, = 100 mm
Using the relation :
E=(RT/ZF) In(Mg out/Mgin)
E = (8.314*298) / (2*96485) * In(100/0.1)
E = (2477.572 / 192970) * 6.9077552
E = 0.0128391 * 6.9077552
E = 0.0886897 V
E = 88.68 mV (approximately 90 mV)
Label one of the test tubes Fe2+. Add 4 milliliters of iron(II) sulfate to the test tube.
Label the other test tube Fe3+. Add 4 milliliters of iron(III) nitrate to the test tube.
Add 4 milliliters of potassium thiocyanate to each test tube.
Observe the contents of the test tubes, noting any evidence of a chemical reaction. Record your observations in the table. If there is no evidence of a reaction, write “no reaction.”
Answer: A: Has little to no reaction; might turn slightly red in color. B: The liquid grows darker in color to a more reddish tone.
Explanation: I didn’t have the necessary materials to complete the experiment so the teacher told me and I put it in my own words.
What is the density of an object that has a mass of 28.1g and a volume of 96.2mL? Select the correct answer below: 0.292g/mL 2703g/mL 1.00g/mL 3.42g/mL
Answer:
0.292 g/mL.
Explanation:
From the question given above, the following data were obtained:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density of an object is simply defined as the mass of the object per unit volume of the object. Mathematically, it can be expressed as:
Density = mass / volume
With the above formula, we can obtain the density of the object as follow:
Mass of object = 28.1 g
Volume of object = 96.2 mL
Density of object =..?
Density = mass / volume
Density = 28.1 / 96.2
Density of object = 0.292 g/mL
Thus the density of the object is 0.292 g/mL
If an oxygen molecule is moving at 4.78 x 104
cm.s-, what is its speed in mi hrl?
Show work please
Answer: 1075.5 mph
Explanation:anything moving at 4.78*10^4 cm/sec
equivalent to
cm —> miles = 1/1.6*10^5
sec —> hr = 1/3600
[4.78*10^4]*3600/1.6*10^5 = 1075.5 mph
Gaseous methane (CH4) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). If 28.2 g of carbon dioxide is produced from the reaction of 15.1 g of methane and 81.2 g of oxygen gas, Calculate the percent yield of carbon dioxide. Be sure your answer has the correct number of significant digits in it.
Answer:
68.1% is percent yield of the reaction
Explanation:
The reaction of methane with oxygen is:
CH₄ + 2O₂ → CO₂ + 2H₂O
Where 2 moles of oxygen react per mole of CH₄
Percent yield is:
Actual yield (28.2g CO₂) / Theoretical yield * 100
To solve this question we need to find theoretical yield finding limiting reactant :
Moles CH₄:
15.1g CH₄ * (1mol / 16.04g) = 0.9414 moles
Moles O₂:
81.2g * (1mol / 32g) = 2.54 moles
For a complete reaction of 0.9414 moles of CH₄ are needed:
0.9414 moles CH₄ * (2 mol O₂ / 1mol CH₄) = 1.88 moles of O₂. As there are 2.54 moles, O₂ is in excess and CH₄ is limiting reactant
In theoretical yield, the moles of methane added = Moles of CO₂ produced. That is 0.9414 moles CO₂. In grams = Theoretical yield:
0.9414 moles CO₂ * (44.01g / mol) = 41.43g CO₂
Percent yield: 28.2g CO₂ / 41.43g CO₂ * 100=
68.1% is percent yield of the reactionDraw the major organic product in the reaction scheme. Be sure to clearly show stereochemistry (if applicable).The starting material is an alkyne where carbon 1 is bonded to cyclopentane and carbon 2 is bonded to H. Step 1 is N a N H 2. Step 2 is C H 3 I. Step 3 is sodium in liquid ammonia.
Answer:
See explanation below
Explanation:
According to what you state in the problem, we have an ethyne bonded to a cyclopentane.
So, in the 1st step reacts with NaNH₂. In this step, the base which is very strong will substract the hydrogen from carbon 2, forming an anion in there. In the second step, this anion will react with CH₃I, and form a larger chain, the methyl group is attached to the alkyne.
Finally in the last step reacts with sodium in ammonia, this is to reduct the triple bond to just a single bond and leave an alkane only. The picture below shows these steps.
Hope this helps.
Which of the following is an example of a physical change, but not a chemical change?
Answer:
Boiling Water
Explanation:
Boiling water is an example of physical change and not and not a chemical change because the water vapor still has the same molecular structure as liquid water.If the bubbles were caused by the decomposition of a molecule into gas then boiling would be a chemical change.
Answer:
A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding
Explanation:
What important function do currents and areas of upwelling provide for living things
in the sea?
Recycles the ocean water through evaporation and precipitation
Brings nutrients up from deeper water for use by organisms
Mixes land and sea organisms to broaden the food web
Allows Earth to have weather and climate changes
True or false questions?
Most metal elements are brittle and do not conduct electricity. True or False
Any element can be identified by counting the protons in its neucleus. True or False
All Earths matter is made from the combination of about 100 elements. True or false
Answer:
1. False 2.True3.True? Unsure
Explanation: