Factors Affecting Rate of Reaction

Q. The rate at which a substance reacts depends upon:

1. Atomic weight
2. Atomic number
3. Molecular weight
4. Active mass

Q. Which of these does not influence the rate of reaction?

1. Nature of the reactants
2. Concentration of the reactants
3. Temperature of the reactions
4. Molecularity of the reaction

Q. The scientist "Q" was experimenting to revive a giant called the Mountain. He accidentally dropped a vial of ammonia on the ground. He saw ammonia react with oxygen and produce NO and water.

Lets say the rate of formation of NO is 3.6 x 10^-3 $M{s}^{-1}$

Calculate

• The rate of disappearance of ammonia
• Rate of formation of water

1. 3.6 x 10^-3 $M{s}^{-1}$ and 3.6 x 10^-3 $M{s}^{-1}$
2. 7.2 x 10^-3 $M{s}^{-1}$ and 3.6 x 10^-3 $M{s}^{-1}$
3. 3.6 x 10^-3 $M{s}^{-1}$ and 5.4 x 10^-3 $M{s}^{-1}$
4. 9 x 10^-3 $M{s}^{-1}$ and 5.4 x 10^-3 $M{s}^{-1}$

Q.

Lanny tried to make cake by mixing the following ingredients in a dark room.

1. Eggs

2. Butter

3. Flour

4. A catalyst-baking powder.

Assuming they undergo a violent reaction to form cake, which of the following may affect the rate of the reaction.

1. A dragon breathing flames on the vessel.

2. Concentration of the eggs

3. Amount of flour
4. Performing it in a sunny beach.

Q. Which of these does not influence the rate of reaction?

1. Nature of the reactants
2. Concentration of the reactants
3. Temperature of the reactions
4. Molecularity of the reaction

Q.

Consider the chemical reaction,
$N_2\left(g\right)+3H_2\left(g\right)\to 2N{H}_3\left(g\right)$
The rate of this reaction can be expressed in terms of time derivatives of concentration of $N_2\left(g\right),H_2\left(g\right)orN{H}_3\left(g\right)$. Identify the correct relationship amongst the rate expressions.

1. $Rate=-\frac{d\left[N_2\right]}{dt}=-3\frac{d\left[H_2\right]}{dt}=2\frac{d\left[N{H}_3\right]}{dt}$

2. $Rate=-\frac{d\left[N_2\right]}{dt}=-\frac{1}{3}\frac{d\left[H_2\right]}{dt}=\frac{1}{2}\frac{d\left[N{H}_3\right]}{dt}$

3. $Rate=\frac{d\left[N_2\right]}{dt}=\frac{1}{3}\frac{d\left[H_2\right]}{dt}=\frac{1}{2}\frac{d\left[N{H}_3\right]}{dt}$

4. $Rate=-\frac{d\left[N_2\right]}{dt}=-\frac{d\left[H_2\right]}{dt}=\frac{d\left[N{H}_3\right]}{dt}$

Q.

Which of the following does NOT affect the rate of a chemical reaction?

1. enthalpy of the reaction

2. concentration of reactants

3. temperature

4. surface area

Q.

Reaction rates can change with

1. temperature

2. the addition of a catalyst

3. reactant concentrations

4. all of these

Q.

As temperature increases, the rate of reaction

1. decreases and increases
2. decreases
3. increases
4. stays the same

Q. For a reaction $2N_2{O}_5\left(g\right)$$\to 4N{O}_2\left(g\right)+O_2\left(g\right)$ , the rate and rate constant are $1.02\times {10}^{-4}$ $mol{L}^{-1}{s}^{-1}$ and $3.4\times {10}^{-5}{s}^{-1}$ respectively. The concentration of $N_2{O}_5$ at this time will be:

1. 1.732 mol/L
2. 3 mol/L
3. $1.02\times {10}^{-4}$ mol/L
4. $3.2\times {10}^5$ mol/L