Why do living things use enzymes instead of heat as a source of activation energy?


Adding heat would not give the reactants enough energy.


Adding heat does not affect how chemical reactions take place.


Adding sufficient heat would harm or kill a living thing.


Adding heat gives reactants the wrong kind of energy.

Virtually all chemical reactions are accompanied by the liberation or uptake of heat. If we regard heat as a "reactant" or "product" in an endothermic or exothermic reaction respectively, we can use the Le Châtelier principle to predict the direction in which an increase or decrease in temperature will shift the equilibrium state. Thus for the oxidation of nitrogen, an endothermic process, we can write

[heat] + N2(g) + O2(g) → 2 NO(g)

Suppose this reaction is at equilibrium at some temperature T1 and we raise the temperature to T2. The Le Châtelier principle tells us that a net reaction will occur in the direction that will partially counteract this change. Since the reaction is endothermic, a shift of the equilibrium to the right will take place.

Answer:

C. the reactants will be favored.

Explanation:

Answer:What is the hydronium ion concentration in a solution of HCl that has a pH of 4.65? Round to the nearest hundredth.
 
2.24 × 10n Mn =  -5

What is the hydroxide ion concentration in a solution of NH3 with a pOH of 4.65?  Round to the nearest hundredth.

2.24 × 10n Mn =  -5

Explanation:

The solubility product constant (Ksp) of calcium carbonate is used to calculate the solubility of this compound in water. Considering the 1:1:1 molar ratio between CaCO3 and the ions it forms on dissolution, we derive the solubility as 0.0058 g/l.

The subject of your question is the solubility product constant (Ksp) of calcium carbonate (CaCO3). The Ksp is used to calculate the solubility of a compound, such as CaCO3, in a given solvent, which in this case is water. The Ksp is given as 3.36 × 10-9 M² and it is this value that we will use to determine the solubility.

As we know, for the dissolution of calcium carbonate into calcium and carbonate ions, the dissolution reaction can be written as: CaCO3(s) → Ca²+ + CO3²-. Here, it implies that there is a 1:1:1 molar ratio between CaCO3 and the ions it forms on dissolution. Thus, if 's' represents the molarity of CaCO3, then the Ksp expression can be written as Ksp = [Ca²+][CO3²-] = s².

Using the given Ksp value, we can solve the above equation for 's': s = sqrt(Ksp) = sqrt(3.36 × 10-9 M²) = 5.8 × 10-5 M. However, the question asks for the solubility in g/l. To convert molarity (M) to g/l, we multiply by the molecular weight of the compound. For CaCO3, the molecular weight is approximately 100 g/mol. Therefore, the solubility is 5.8 × 10-5 M x 100 g/mol = 0.0058 g/l.

https://brainly.com/question/30642058

#SPJ11

Answer:

Friction

Explanation:

Friction is a force that slows down moving objects. If you roll a ball across a shaggy rug, you can see that there are lumps and bumps in the rug that make the ball slow down. The rubbing, or friction, between the ball and the rug is what makes the ball stop rolling.

The chemical formula for tetraphosphorus decasulfide is P4S10, consisting of four phosphorus atoms and ten sulfur atoms in the compound.

The chemical formula for the compound tetraphosphorus decasulfide is P4S10.

Phosphorus forms various compounds with different stoichiometries, and in this case, tetraphosphorus decasulfide consists of four phosphorus atoms bonded with ten sulfur atoms.

It is crucial to understand chemical formulas to identify elements and their quantities in compounds accurately.

Answer is: pH of solution of sodium cyanide is 11.07.
Chemical reaction 1: NaCN(aq) → CN⁻(aq) + Na⁺(aq).
Chemical reaction 2: CN⁻ + H₂O(l) ⇄ HCN(aq) + OH⁻(aq).
c(NaCN) = c(CN⁻) = 0.068 M.
Ka(HCN) =  4.9·10⁻¹⁰.
Kb(CN⁻) = 10⁻¹⁴ ÷ 4.9·10⁻¹⁰ = 2.04·10⁻⁵.
Kb = [HCN] · [OH⁻] / [CN⁻].
[HCN] · [OH⁻] = x.
[CN⁻] = 0.068 M - x..
2.04·10⁻⁵ = x² / (0.068 M - x).
Solve quadratic equation: x = [OH⁻] = 0.00116 M.
pOH = -log(0.00116 M) = 2.93.
pH = 14 - 2.93 = 11.07.

The pH of the sodium cyanide solution is 11.56.

Let the cyanide ion be X

We have to set up the ICE table for the problem as follows;

     X^-(aq) + H2O(l)  ⇄ HX(aq) + OH^-(aq)

I    0.068                            x                 x

C   -x                                 + x                +x      

E   0.068 - x                      x                   x

But Kb = Kw/Ka = 1 × 10^-14/4.9 × 10-10

Kb = 2 × 10^-4

So;

Kb = [HX] [OH^-]/[X^-]

2 × 10^-4 = x^2/ 0.068 - x  

2 × 10^-4(0.068 - x) = x^2

1.36 × 10^-5 - 2 × 10^-4x = x^2

x^2 + 2 × 10^-4x - 1.36 × 10^-5 = 0

x= 0.0036 M

Since x = [OH^-] = 0.0036 M

pOH = - log(0.0036 M)

pOH = 2.44

pH = 14 - 2.44 = 11.56

The pH of the sodium cyanide solution is 11.56.

Learn more about pH: https://brainly.com/question/8139015

Final answer:

To find the volume of oxygen needed to combust 5.53 grams of propane, calculate the moles of propane, use the stoichiometric relationship to find the moles of oxygen required, and then apply the ideal gas law to find the volume, resulting in 14.79 liters of oxygen needed.

Explanation:

Gas Stoichiometry of Propane Combustion

To determine the volume of oxygen at 25 degrees Celsius and 1.04 atm needed for the complete combustion of 5.53 grams of propane, we need to use stoichiometry and the ideal gas law. The balanced equation for the combustion of propane C3H8 is:

C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l)

First, we convert the mass of propane into moles using its molar mass:

5.53 g C3H8 × (1 mol C3H8 / 44.11 g C3H8) = 0.1253 mol C3H8

According to the balanced equation, 1 mole of propane reacts with 5 moles of oxygen. Therefore, we need:

0.1253 mol C3H8 × (5 mol O2 / 1 mol C3H8) = 0.6265 mol O2

Now, we use the ideal gas law, PV=nRT, to find the volume of oxygen. First, adjust R to match the pressure in atm and volume in liters:
1.04 atm × V = 0.6265 mol × 0.0821 L×atm/mol×K × 298.15 K

Solving for V gives us the volume of oxygen needed:

V = (0.6265 mol × 0.0821 L×atm/mol×K × 298.15 K) / 1.04 atm = 14.79 L

Therefore, 14.79 liters of oxygen at 25 degrees Celsius and 1.04 atm are required for the complete combustion of 5.53 grams of propane.

In a fission reaction, the nucleus of an atom splits into fragments, releasing a large amount of energy. Nuclear fission occurs when a heavy nucleus like uranium absorbs a neutron and splits, emitting additional neutrons, gamma rays, and energy.

The correct description of the changes involved in a fission reaction is: The nucleus of an atom splits into fragments, releasing a large amount of energy. Nuclear fission is a nuclear reaction where the nucleus of an atom, such as uranium-235 or plutonium-239, splits into smaller nuclei after absorbing a neutron.

This process produces additional free neutrons, gamma radiation, kinetic energy of fission fragments, and releases a significant amount of energy. The process is exothermic, and the energy released can be harnessed for electricity generation in nuclear reactors or can be used in nuclear weapons.

Nuclear fission differs from nuclear fusion, which is the combining of two smaller atomic nuclei to form a larger nucleus, also releasing energy. In both processes, large amounts of heat and radiation are emitted. However, for fission, a fissile material like uranium or plutonium is necessary to sustain the reaction, and it involves the breakup of a heavy nucleus into lighter elements.

Among C₆H₁₂O₆, C₂H₅OH, CH₃COOH, and NaCl, NaCl is the one that will provide the aqueous solution with the lowest freezing point.

We have 4 aqueous solutions and we want to determine which has the lowest freezing point.

Freezing-point depression is a drop in the temperature at which a substance freezes, caused when a smaller amount of another, non-volatile substance is added.

We can calculate the freezing point depression (ΔT) using the following expression.

ΔT = Kf × b × i

where,

Assuming all the solutions have the same molality, the freezing point depression will be a function of the van't Hoff factor.

The van 't Hoff factor is the ratio between the actual concentration of particles produced when the substance is dissolved and the concentration of a substance as calculated from its mass.

Thus, NaCl, with the highest Van't Hoff factor, will have the lowest freezing point.

Among C₆H₁₂O₆, C₂H₅OH, CH₃COOH, and NaCl, NaCl is the one that will provide the aqueous solution with the lowest freezing point.

Learn more about freezing point depression here: https://brainly.com/question/2292439

Answer:

0.0135 moles of iodine will be formed.

Explanation:

[tex]2NI_3\rightarrow N_2+3I_2[/tex]

Moles of nitrogen triiodide =[tex]\frac{3.58 g}{394.71 g/mol}=0.0090 mol[/tex]

According to reaction 2 moles of nitrogen triiodide gives 3 moles of iodione gas.

Then 0.0090 mol of nitrogen triiodide will give:

[tex]\frac{3}{2}\times 0.0090 mol=0.0135 mol[/tex]

0.0135 moles of iodine will be formed.

Answer: B) increasing the surface area of the reactants.

Explanation:

Decreasing the particle size of the reactants in a chemical reaction will increase the rate of reaction by increasing the surface area of the reactants. Hence, option B is correct.

A chemical reaction is a process that leads to the transformation of one set of chemical substances into another. It involves breaking and forming chemical bonds between atoms and molecules to form new substances.

In a chemical reaction, the reacting substances are called reactants, and the newly formed substances are called products.

Decreasing the particle size of the reactants in a chemical reaction will increase the rate of reaction by increasing the surface area of the reactants that are available for the reaction.

When the particle size is reduced, the total surface area of the reactant particles is increased, which makes it easier for the particles to collide and react with one another.

Thus, option B is correct.

To learn more about the chemical reaction, follow the link:

https://brainly.com/question/29039149

#SPJ2

Explanation:

Plants veins provide energy to the rest of the plant and it also provides structure and support to the plant leaves and also transport water. When plants absorb water and nutrients through their roots, their vascular system come in use to move water and nutrients to the rest part of the plants. There are two types of tissue that make up the plants veins are xylem and phloem. Xylem moves water and minerals from the plants's roots and phloem moves food energy to all parts of plant where the plants need it.    

Final answer:

To prepare 0.50 mL of a 0.15 M NaOH solution from a 6.00 M NaOH solution, you would need 12.5 μL of the concentrated solution according to the dilution formula, which is not listed among the provided answer options.

Explanation:

The volume of 6.00 M NaOH solution required to prepare 0.50 mL of 0.15 M NaOH solution can be found using the dilution formula M1V1 = M2V2, where M1 and V1 are the molarity and volume of the concentrated solution, and M2 and V2 are the molarity and volume of the diluted solution, respectively. Plugging the known values into the equation: (6.00 M)(V1) = (0.15 M)(0.50 mL) ⇒ V1 = (0.15 M)(0.50 mL) / (6.00 M) = 0.0125 mL or 12.5 μL.

Since none of the provided answer choices (a) 12.5 mL, (b) 25 mL, or (c) 30 mL match this result, it seems there might be a typo or a misprint in the question. To prepare 0.50 mL of a 0.15 M solution from a 6.00 M solution, you would need substantially less than 1 mL of the concentrated solution. The likely correct volume needed, based on the question's data, would be 12.5 μL, which is not listed as an option in the question.

Volatile organic compounds (VOCs) can evaporate from fracking liquid waste pools, contributing to air pollution. These pools may also contain hazardous air pollutants and heavy metals, requiring careful handling to avoid environmental contamination.

When fracking liquid waste is left in pools on the surface, volatile organic compounds (VOCs) can evaporate into the air and contribute to pollution. These wastewater ponds can contain a variety of pollutants, including hazardous air pollutants such as benzene, toluene, ethylbenzene, and xylene. Moreover, fracking fluid, also known as flowback, can contain chemicals used in the drilling process, heavy metals, and radioactive materials. These substances pose a significant risk to both environmental and human health if they are not properly managed and treated.

The process of hydraulic fracturing or 'fracking' involves injecting high-pressure fluids to fracture shale deposits, which releases trapped gas and oil. The wastewater from this process may return to the water cycle, but the large volume of contaminated water requires careful handling to prevent land and water pollution. As a proactive measure, governments around the world have taken steps, in some cases banning the practice due to the severe risks associated with fracking.

Final answer:

The final pressure of the system is 0.85 atm.

Explanation:

To determine the final pressure of the system, we can use the relationship between volume and pressure known as Boyle's Law. According to Boyle's Law, when the volume of a gas increases, the pressure decreases, and vice versa, at constant temperature and amount of gas.

In this case, the initial volume is 0.75 L and the final volume is 1.1 L. Since the volume increased, we can expect the pressure to decrease. The initial pressure is 1.25 atm. Using Boyle's Law, we can set up the equation:

P1 * V1 = P2 * V2

1.25 atm * 0.75 L = P2 * 1.1 L

Solving for P2, we get: P2 = 1.25 atm * 0.75 L / 1.1 L = 0.85 atm

Therefore, the final pressure of the system is 0.85 atm.