Kinetics Chemistry

Which statement describes the characteristics of a transition state relative to the potential energy of the reactants and products?

• It is an unstable species with lower potential energy.

• It is an unstable species with higher potential energy.

• It is a stable species with lower potential energy.

• It is a stable species with higher potential energy.

Which pair of graphs represents the same order of reaction?

• A

• B

• C

• D

Decomposition of hydrogen peroxide in an aqueous solution proceeds as follows. 2H2O2(aq) → 2H2O(l) + O2(g) The rate expression for the reaction was found to be: rate = k [H2O2]. Which graph is consistent with the given rate expression?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-5

Which statement about a first-order reaction is correct?

• The reactant concentration decreases linearly with time.

• The reactant concentration decreases exponentially with time.

• The rate of reaction remains constant as the reaction proceeds.

• The rate of reaction increases exponentially as the reaction proceeds.

Tags

NGSS.HS-PS1-5

Consider the rate expression: Rate=k[X][Y] Which change decreases the value of the rate constant, k?

• Increase in the reaction temperature

• Decrease in the reaction temperature

• Increase in the concentration of X and Y

• Decrease in the concentration of X and Y

Tags

NGSS.HS-PS1-5

What are the units of the rate constant for a zero-order reaction?

• s

• s−1

• mol−1 dm3s−

• mol dm−3 s−1

Tags

NGSS.HS-PS1-5

Consider the following reaction between nitrogen monoxide and oxygen. 2NO(g)+O2(g)→2NO2(g) The reaction occurs in two steps: Step 1: NO(g)+NO(g)⇌N2O2(g) fast Step 2: N2O2(g)+O2(g)→2NO2(g) slow What is the rate expression for this reaction?

• Rate =k[NO]²

• Rate =k[NO][O₂]

• Rate =k[NO]²[O₂]

• Rate =k[NO][O₂]²

Tags

NGSS.HS-PS1-5

X and Y react according to the equation 2X+Y→Z. The reaction can be described by the following mechanism:

X+X→X2. slow

X2+Y→Z fast

What is the order of the reaction with respect to X and Y?

• X - first; Y - 0

• X - first; Y - first

• X - second; Y - 0

• X - second; Y - first

Which combination shows a second-order rate expression with the correct rate constant units?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-5

The following experimental rate data were obtained for a reaction carried out at temperature T.

A(g)+B(g)→C(g)+D(g)

• Order with respect to A (g) = zero ; Order with respect to B (g) = second

• Order with respect to A (g) = first ; Order with respect to B (g) = zro

• Order with respect to A (g) = second ; Order with respect to B (g) = zero

• Order with respect to A (g) = second ; Order with respect to B (g) = first

Tags

NGSS.HS-PS1-5