Rates of Reaction - exam practice

A reactant Q is converted into two products.

Which of these graphs shows that this reaction is first order with respect to Q?

To determine the activation energy, E_a , for a reaction, a graph was plotted of ln k against 1/T, where k is the rate constant.

The Arrhenius equation is

The gradient of the graph is equal to

For a given initial reactant pressure, the half-life for a first order gaseous reaction was found to be 30 minutes.

If the experiment were repeated at half the initial reactant pressure, the half-life would be

Which statement about the rate determining step of a reaction is correct?

Nitrogen dioxide reacts with carbon monoxide as in the equation below.

NO₂ + CO ➔ NO + CO₂

The mechanism is:

NO₂ + NO₂ ➔ NO + NO₃ Slow

NO₃ + CO ➔ NO₂ + CO₂ Fast

Which expression is the correct rate equation?

A student plots ln k (y-axis) against 1/T (in K^-1) for a reaction. The student gets a straight line graph that corresponds to the Arrhenius equation:

Which statement is correct?

A graph is plotted of ln k against 1/T.

(k = rate constant, T = temperature in K)

The gradient has the numerical value of -55,000.

What is the activation energy, in kJ mol^-1?

The equation for the reaction of ICl and H₂ is shown below.

2ICl_(g) + H₂(g) ➔ 2HCl_(g) + I_2(g)

The rate constant k for this reaction is 1.63 × 10^-6 dm³ mol^-1 s^-1.

What is the overall order of the reaction?

Solutions of two compounds, W and X, react together in the presence of a soluble catalyst, Y, as shown in the equation

2W + X ➔ Z

When the concentrations of W, X and Y are all doubled, the rate of reaction increases by a factor of four.

Which is a possible rate equation for this reaction?

The rate equation for the hydrogenation of ethene:

C₂H_4(g) + H_2(g) ➔ C₂H_6(g)

is rate = k[C₂H₄][H₂].

At a fixed temperature, the reaction mixture is compressed to triple the original pressure.

What is the factor by which the rate of reaction changes?

The rate expression for the reaction between X and Y is

rate = k [X]²[Y]

Which statement is correct?

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

The results of an investigation of the reaction between P and Q are shown in this table.

The rate equation is: rate = k[P][Q]²

What is the initial concentration of Q in experiment 2?

What is the effect of increasing temperature on the rate contant, K?

Which is true of an Arrhenius plot of lnk (y-axis) against $\frac{1}{T}$?

The rate expression for the reaction X_(g) + 2Y_(g) ➔ 3Z_(g) is

rate = k[X]⁰[Y]²

By which factor will the rate of reaction increase when the concentrations of X and Y are both increased by a factor of 3?

Which is correct about reaction mechanisms?

The reaction between NO₂ and F₂ gives the following rate data at a certain temperature.

What is the overall order of reaction ?

2NO_(g) + O_2(g) ➔ 2NO_2(g)

The rate equation for the reaction above is rate = k[NO]²[O₂]

Which statement is not correct?

The inorganic anti-cancer drug cis-platin, Pt(NH₃)₂Cl₂, is hydrolysed by water to make it active. The reaction is

Pt(NH₃)₂Cl₂ + H₂O ➔ [Pt(NH₃)₂(H₂O)Cl]⁺ + Cl^-

The hydrolysis is first order overall. The half-life can be found from a graph of the concentration of cis-platin against time.

The half-life of the reaction is...