Chemical Kinetics

Decreases by half

Increases by 10 times

Remains constant

Increases by 2 to 3 times

Average rate

Initial rate

Instantaneous rate

Specific rate

Rate $= -\frac{d[A]}{dt}$

Rate $= -\frac{1}{2}\frac{d[A]}{dt}$

Rate $= -2\frac{d[A]}{dt}$

Rate $= \frac{1}{2}\frac{d[A]}{dt}$

The value of the rate constant $k$ increases.

The activation energy barrier is lowered.

The number of collisions per unit volume per unit time increases.

The average kinetic energy of the molecules increases.

The powder has a higher kinetic energy.

The powder provides a larger surface area for collisions to occur.

The activation energy for the powder is lower.

The concentration of the acid increases when reacting with powder.

It increases the total enthalpy change of the reaction.

It is consumed in the reaction to form a stable intermediate.

It provides an alternative reaction pathway with a lower activation energy.

It shifts the equilibrium position to favor the formation of products.

2

1.5

2.5

1

The sum of powers of the concentration terms in the rate law.

The number of reacting species colliding simultaneously in an elementary step.

The total number of product molecules formed in a balanced equation.

The ratio of the rate of reaction to the concentration of reactants.

$s^{-1}$

$L\ mol^{-1}\ s^{-1}$

$mol\ L^{-1}\ s^{-1}$

$L^2\ mol^{-2}\ s^{-1}$

$[A]_t = [A]_0 - kt$

$ln[A]_t = ln[A]_0 - kt$

$[A]_t = [A]_0 \, e^{-kt}$

$k = \frac{2.303}{t} log \frac{[A]_0}{[A]_t}$

$-k$

$k / 2.303$

$-k / 2.303$

$2.303 / k$

It is doubled

It remains unchanged

It is halved

It increases fourfold

$1.0 \times 10^{-2} s^{-1}$

$1.0 \times 10^{-3} s^{-1}$

$6.93 \times 10^{-1} s^{-1}$

$0.693 s^{-1}$

$t_{1/2} = \frac{[A]_0}{2k}$

$t_{1/2} = \frac{2k}{[A]_0}$

$t_{1/2} = \frac{0.693}{k}$

$t_{1/2} = \frac{[A]_0}{k}$

It is independent of $[A]_0$.

It is inversely proportional to $[A]_0$.

It is directly proportional to $[A]_0$.

It is proportional to the square of $[A]_0$.

The reaction will be extremely slow

The reaction will not occur

The reaction will be very fast

The rate will be independent of temperature

The total number of collisions per second per unit volume of the reaction mixture

The number of molecules reacting per unit time

The number of effective collisions per mole of reactant

The velocity with which molecules collide

The molecules must collide in a vacuum

The molecules must have high potential energy only

The molecules must have a proper orientation and energy equal to or greater than the threshold energy

The molecules must be in the gaseous state at STP

The frequency factor ($A$)

Zero

Infinity

The gas constant ($R$)

Activation energy per mole

The frequency factor or pre-exponential factor

The absorption coefficient

The average kinetic energy

It decreases $E_a$ and increases the rate

It increases $E_a$ and increases the rate

It decreases $E_a$ and decreases the rate

It has no effect on $E_a$ but increases the rate

Potential energy

Activation energy

Kinetic energy

Enthalpy of reaction

It decreases exponentially

It remains constant regardless of temperature

It increases exponentially

It increases linearly

$-E_a / R$

$-E_a / 2.303R$

$E_a / R$

$2.303 R / E_a$