URGENT PLZ HELP
Which of the following statements is true?
a. In an endothermic process heat is transferred from the surroundings to the
system.
b. In an exothermic process heat is transferred from the surroundings to the
system.
C. The surroundings will feel cooler in an exothermic process.
d. The surroundings will feel warmer in an endothermic process.
Answer:
A.
Explanation:
In an endothermic reaction heat is applied.
In an endothermic process, heat is transferred from the surroundings to the system.
What are endothermic and exothermic processes?
An exothermic process is one that gives off heat. This heat is transferred to the surroundings. An endothermic process is one in which heat has to be supplied to the system from the surroundings.
The endothermic process is a term that describes a reaction where the system absorbs the energy from its surrounding in the form of heat. A few examples of the endothermic process are photosynthesis, evaporating liquids, melting ice, etc.
The exothermic reaction is the opposite of an endothermic reaction. It releases energy by light or heat to its surrounding. A few examples are neutralization, burning of a substance, reactions of fuels, etc.
Hence, option A is the correct answer.
Learn more about endothermic and exothermic processes here:
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What is neutralisation reaction? Give an example with reaction involved. State two uses of neutralisation reaction in everyday life.
Answer:
neutralization reaction is when an acid and a base react to form water and salt and involves the combination of hydrogen ions and hydroxyl ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7.
Which of the following compounds is least soluble in water?
A) iron (III) chloride
B) ammonium acetate
C) sodium hydroxide
D) magnesium carbonate
Answer:
B
Explanation:
1. What do producers do, and what is another name for them?
Producers are the foundation of every food web in every ecosystem—they occupy what is called the first tropic level of the food web. The second trophic level consists of primary consumers—the herbivores, or animals that eat plants. At the top level are secondary consumers—the carnivores and omnivores who eat the primary consumers. Ultimately, decomposers break down dead organisms, returning vital nutrients to the soil, and restarting the cycle. Another name for producers is autotrophs, which means “self-nourishers.” There are two kinds of autotrophs. The most common are photoautotrophs—producers that carry out photosynthesis. Trees, grasses, and shrubs are the most important terrestrial photoautotrophs. In most aquatic ecosystems, including lakes and oceans, algae are the most important photoautotrophs.
When you work out your cells need
Answer:
Waterrrr
Explanation:
H2O
Answer:
Muscle contraction
Explanation:
According to the new study, exercise improves muscle health by renewing its cellular powerhouse: the mitochondria. Mitochondria are crucial to the good functioning of our bodies, as well as to our overall health and longevity. These tiny parts of the cell turn the food we eat into energy.
Answer the following questions about the solubility of CoCO3(s). The value of Ksp for CoCO3(s) is 1.0 × 10^−10.
A. Calculate the value of [Co2+] in a saturated solution of CoCO3 in distilled water.
B. If 0.10 M of Co2+ is already present in distilled water, calculate the molar solubility of CoCO3(s).
C. Explain why CoCO3 is less soluble in distilled water that already contains Co2+
Answer:
Attached picture.
Explanation:
(1) Ksp equals the product of [Co 2+][CO3 2-]. CoCO3 is excluded from the equilibrium expression because it is a pure solid. The mole ratio of Co 2+ and CO3 2- is 1:1 so their molar solubilities are the same.
(2) There is an initial concentration of 0.10 M Co 2+ so write that in the "I" row for Co 2+ on the ICE table. When you find the zeros of the quadratic when solving for "s", take the positive value rather than the negative value because concentration cannot be negative.
(3) Extra products will cause the equilibrium to consume products and form reactants. So the reverse reaction will occur faster than the forward reaction. More products mean an increased Q value compared to K, since the numerator of [tex]K = \frac{[products]}{[reactants]}[/tex] increases.
If a compressed air cylinder for scuba diving contains 6.0 L of gas at 18°C and 200 atm pressure, what volume does the gas occupy at 1.0 atm and 25°C?
Answer:
[tex]V_2=1228.9L[/tex]
Explanation:
Hello there!
In this case, given the pressure, temperature and volume of the gas, we notice that we need the combined ideal gas as shown below:
[tex]\frac{P_2V_2}{T_2} =\frac{P_1V_1}{T_1}[/tex]
Thus, solving for the final volume, V2, we would obtain:
[tex]V_2=\frac{P_1V_1T_2}{T_1P_2}[/tex]
Now, we plug in the data and make sure the temperature must be in Kelvins to obtain:
[tex]V_2=\frac{200atm*6.0L*(25+273)K}{(18+273.15)K(1.0atm)}\\\\V_2=1228.9L[/tex]
Best regards!
The following solutions are prepared by dissolving the requisite amount of solute in water to obtain the desired concentrations. Rank the solutions according to their respective osmotic pressures in decreasing order assuming the complete dissociation of ionic compounds. Rank from highest to lowest osmotic pressure. To rank items as equivalent, overlap them.
A. 1 M MgCl2
B. 1 M KCI
C. 1 M C12
D. H22011
1. Highest osmotic pressure
2. Lowest osmotic pressure
Answer: 1. Highest osmotic pressure : 1 M [tex]MgCl_2[/tex]
2. Lowest osmotic pressure: 1 M [tex]C_{12}H_{22}O_{11}[/tex]
Explanation:
[tex]\pi=i\times C\times R\times T[/tex]
[tex]\pi[/tex]= osmotic pressure
i = Van'T Hoff factor
C = concentration
T = Temperature
1. For 1M [tex]MgCl_2[/tex]
, i= 3 as it is a electrolyte and dissociate to give 3 ions.
[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^{-}[/tex]
2. For 1 M [tex]KCl[/tex]
, i= 2 as it is a electrolyte and dissociate to give 2 ions.
[tex]KCl\rightarrow K^{+}+Cl^{-}[/tex]
3. For 1M [tex]C_{12}H_{22}O_{11}[/tex]
, i= 1 as it is a non electrolyte and do not dissociate.
Thus as vant hoff factor is highest for [tex]MgCl_2[/tex] thus osmotic pressure is highest for 1 M [tex]MgCl_2[/tex]
And as vant hoff factor is lowest for [tex]C_{12}H_{22}O_{11}[/tex] thus osmotic pressure is lowest for 1 M [tex]C_{12}H_{22}O_{11}[/tex]
Oxalic Acid, a compound found in plants and vegetables such as rhubarb, has a mass percent composition of 26.7% C, 2.24% H, and 71.1% O. Oxalic acid can interfere with respiration and cause kidney or bladder stones. If a large quantity of rhubarb leaves is ingested, the oxalic acid can be toxic. The lethal dose (LD50) in rats for oxalic acid is 375 mg/kg. Rhubarb leaves contain about 0.5% by mass of oxalic acid. (Show your work, using the insert equation tool :) What is the empirical formula of oxalic acid
Answer:
HCO₂
Explanation:
From the information given:
The mass of the elements are:
Carbon C = 26.7 g; Hydrogen H = 2.24 g Oxygen O = 71.1 g
To determine the empirical formula;
First thing is to find the numbers of moles of each atom.
For Carbon:
[tex]=26.7 \ g\times \dfrac{1 \ mol }{12.01 \ g} \\ \\ =2.22 \ mol \ of \ Carbon[/tex]
For Hydrogen:
[tex]=2.24 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =2.22 \ mol \ of \ Hydrogen[/tex]
For Oxygen:
[tex]=71.1 \ g\times \dfrac{1 \ mol }{1.008 \ g} \\ \\ =4.44 \ mol \ of \ oxygen[/tex]
Now; we use the smallest no of moles to divide the respective moles from above.
For carbon:
[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ carbon[/tex]
For Hydrogen:
[tex]\dfrac{2.22 \ mol \ of \ carbon}{2.22} =1 \ mol \ of \ hydrogen[/tex]
For Oxygen:
[tex]\dfrac{4.44 \ mol \ of \ Oxygen}{2.22} =2 \ mol \ of \ oxygen[/tex]
Thus, the empirical formula is HCO₂
LEVEL 3
Write the correct order
of letters to the finish line.
A E B E C
Example:
ABCGH
G
H
N
eza
Not correct
which wet land is known for the large trees in the water known as bottomland hardwoods?
A. Central Texas
B.South Texas
C. East texas
plz, help me I'm so confused!
(this is also science)
Answer:
Well, there is no photo...
Explanation:
PLEASE HELPPP WILL GIVE 10 PTS AND MARK BRAINIEST TO RIGHT ANSER!!!!!
Roasted coffee beans contain over_____________ chemical compounds
A) 10000000
B) 1000000
C) 1000
D) 10000
Answer:
C. 1000
l think this is correct answer
l hope it's helpful for you
Why do atoms connect to eachother?
Answer:
To keep from falling apart
Explanation:
Ca and F what are the name of the ionic compounds
Answer:
Calcium flouride?
Explanation:
Quite self explanatory
Methane and sulfur react to produce carbon disulfide (CS₂), a liquid often used in the production of cellophane.
2CH₄ + S₈ --> 2CS₂ + 4H₂S
Calculate the moles of H₂S produced when 2.25 mol S₈ is used.
Answer:
9 moles
Explanation:
The balanced chemical equation provided in this question is as follows:
2CH₄ + S₈ → 2CS₂ + 4H₂S
In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).
Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol
9 moles of H2S is produced.
17. The equation below represents a chemical reaction that occurs in living cells.
CoH1206 + 602 -- 6002 + 6H20 + energy
How many atoms are represented in the reactants of this equation?
Answer:
36 atoms
Explanation:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energyThe reactants are in the left side of the equation. First we determine how many atoms are there in the C₆H₁₂O₆ molecule:
6 C atoms + 12 H atoms + 6 O atoms = 24 atoms in totalThere are two atoms in a O₂ molecule, and there are 6 O₂ molecules in the equation:
2 * (6 O atoms) = 12 atoms in totalThe total number of atoms in the reactants is
24 + 12 = 36 atomsHelp me! Who ever gets to answer and has the best answer gets brainliest (very easy!)
Answer:
Fires --> These consume fuel and convert chemical energy stored in that fuel into thermal light and sound energy.
Decay -->The breakdown of dead plants and animals releases thermal energy.
Earth --> Thermal energy comes from deep inside and it is called geothermal energy.
how many atoms of carbon are in a diamond with a mass of 0.568 g?
Answer:
There are 2.85 x 10^22 atoms of carbon in a diamond with a mass of 0.568 g.
Hope this helps! :)
In an electrical circuit, the presence of a resistor limits the current and prevents
damage related to short circuits.
True or
False
What class of chemicals is responsible for ozone depletion?
What is created when an acid is mixed with a base?
Answer:
If you mix equal amounts of a strong acid and a strong base, the two chemicals essentially cancel each other out and produce a salt and water. Mixing equal amounts of a strong acid with a strong base also produces a neutral pH (pH = 7) solution.
Which property increases as you move down a column in the periodic table?
A) atomic size
B) ionization energy
C) nonmetallic character
D) none of the above (all increase as you move down a column).
Answer:
A) atomic size
Explanation:
#7 which of the following decreases the rate of solubility of solid molecules in a solution?
Answer:
7. Option D
Explanation:
Solubility increases with the increase in temperature of the solution. It is so because the increase in temperature leads to increase in kinetic energy which then breaks the solute particles held together by intermolecular attractions.
Hence, option D is correct
A student prepared a stock solution by dissolving 20.0 g of NaOH in enough water to make 150. mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough water to make 65.0 mL of a final solution. What is the concentration of NaOH for the final solution
Answer:
[tex]0.769\ \text{M}[/tex]
Explanation:
Mass of stock solution = 20 g
Molar mass of NaOH = 40 g/mol
Volume of stock solution = 0.150 mL
[tex]M_2[/tex] = Concentration of NaOH for the final solution
[tex]V_1[/tex] = Amount of stock solution taken = 15 mL
[tex]V_2[/tex] = Total volume of solution = 65 mL
Molarity is given by
[tex]M_1=\dfrac{\text{Mass}}{\text{Molar mass}\times \text{Volume}}\\\Rightarrow M_1=\dfrac{20}{40\times 0.15}\\\Rightarrow M_1=\dfrac{10}{3}[/tex]
We have the relation
[tex]M_1V_1=M_2V_2\\\Rightarrow M_2=\dfrac{M_1V_1}{V_2}\\\Rightarrow M_2=\dfrac{\dfrac{10}{3}\times 15}{65}\\\Rightarrow M_2=0.769\ \text{M}[/tex]
The concentration of NaOH for the final solution is [tex]0.769\ \text{M}[/tex].
What happened during the fusion reaction shown? 2H Зн 4He neutron O A. Two H nuclei fused into one He nucleus. O B. One He nucleus split into two H nuclei. O C. The nuclei that fused lost all their neutrons. D. The nuclei that fused lost some of their protons.
Answer: C.
Explanation:
two H nuclei fused into one He nucleus
Answer: A!
Explanation: just did it
How many molecules of H20 are present in 7.30 g of water?
Answer:
2.44×10²³ molecules
Explanation:
From the question given above, the following data were obtained:
Mass of H₂O = 7.30 g
Number of molecules of H₂O =?
From Avogadro's hypothesis:
1 mole of H₂O = 6.02×10²³ molecules
1 mole of H₂O = (2×1) + 16
= 2 + 16
= 18 g
Thus,
18 g of H₂O = 6.02×10²³ molecules
Finally, we shall determine the number of molecules present in 7.3 g of H₂O. This can be obtained as follow:
From Avogadro's hypothesis:
18 g of H₂O = 6.02×10²³ molecules
Therefore,
7.3 g of H₂O = 7.3 × 6.02×10²³ / 18
7.3 g of H₂O = 2.44×10²³ molecules
Thus, 7.3 g of H₂O contains 2.44×10²³ molecules
Consider the reaction of tin with potassium hydroxide and water. Sn (s) 2KOH (aq) 4H2O (l) K2Sn(OH)6 (s) 2H2 (g) Determine the limiting reactant in a mixture containing 122 g of Sn, 134 g of KOH, and 63.9 g of H2O. Calculate the maximum mass (in grams) of potassium hydroxystannate, K2Sn(OH)6, that can be produced in the reaction. The limiting reactant is:
Answer:
The limiting reactant is: H₂O
265.3 g of K₂Sn(OH)₆ are formed in the reaction.
Explanation:
The reaction is:
Sn(s) + 2KOH (aq) + 4H₂O(l) → K₂Sn(OH)₆ (s) + 2H₂ (g)
The first step to solve is to determine the moles of each reactant:
We controlled that reaction is ballanced.
122 g . 1mol / 118.71g = 1.03 moles of Sn
134g . 1mol /56.1g = 2.39 moles of KOH
63.9 g .1mol /18g = 3.55 mol of water
Stoichiometry is 1:2:4.
Sn is the lowest reactant and water, the highest, but I can see, that water is the limiting.
1 mol of Sn needs 4 moles of H₂O to react
Then, 1.03 moles of Sn may react to (1.03 . 4)/1 = 4.12 moles.
We only have 3.55 moles. It's ok.
2 moles of KOH need 4 moles of H₂O to react
Then, 2.39 moles of KOH may react to (2.39 . 4) /2 = 4.78 moles.
We only have 3.55, there's no enough water.
So 4 moles of water can produce 1 mol of potassium hydroxystannate
Then, 3.55 moles of H₂O may produce (3.55 . 1)/4 = 0.8875 moles.
We convert moles to mass: 0.08875 mol . 298.91g /1mol =265.3g
Questions:
1. Are humans getting plastic only from seafood? Explain:
2. Why is it difficult to say that plastics are directly causing illnesses?
3. What could be some of the negative effects of plastics on the
human body?
4. Why is the scientist Shanna Swan worried about the future of
humankind?
Answer:
Explanation:1. It is known that humans are in fact eating these tiny plastic particles, but fish aren't the only source. Bottled water, beer, honey, sea salt and tea bags have all been exposed as microplastic carriers, just to name a few.
2.The chemicals used in the production of plastic are toxic and detrimental to the human body. Chemicals in plastic-like lead, cadmium and mercury directly can come in contact with the humans. These toxins can cause cancers, congenital disabilities, immune system problems and childhood development issues.
3.Microplastics entering the human body via direct exposures through ingestion or inhalation can lead to an array of health impacts, including inflammation, genotoxicity, oxidative stress, apoptosis, and necrosis, which are linked to an array of negative health outcomes including cancer, cardiovascular diseases,
4.Human penises are shrinking because of pollution, warns scientist. ... Dr Shanna Swan writes that humanity is facing an "existential crisis" in fertility rates as a result of phthalates, a chemical used when manufacturing plastics that impacts the hormone-producing endocrine system
Calculate the pH of a solution containing 25 g of barium hydroxide (171.34 mel) dissolved in 250 mL of
solution.
Answer:
14
Explanation:
Step 1: Calculate the moles corresponding to 25 g of Ba(OH)₂
The molar mass of Ba(OH)₂ is 171.34 g/mol.
25 g × 1 mol/171.34 g = 0.15 mol
Step 2: Calculate the molar concentration of Ba(OH)₂
Molarity is equal to the moles of solute divided by the liters of solution.
[Ba(OH)₂] = 0.15 mol/0.250 L = 0.60 M
Step 3: Calculate the molar concentration of OH⁻
Ba(OH)₂ is a strong base according to the following equation.
Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻
The molar ratio of Ba(OH)₂ to OH⁻ is 1:2. The molar concentration of OH⁻ is 2/1 × 0.60 M = 1.2 M.
Step 4: Calculate the concentration of H⁺
We will use the ionic product of water expression.
Kw = 1.0 × 10⁻¹⁴ = [H⁺] × [OH⁻]
[H⁺] = 1.0 × 10⁻¹⁴/[OH⁻] = 1.0 × 10⁻¹⁴/1.2 = 8.3 × 10⁻¹⁵ M
Step 5: Calculate the pH of the solution
We will use the definition of pH.
pH = -log [H⁺] = -log 8.3 × 10⁻¹⁵ = 14