Rates, Equilibrium and PH

Question 1

What is the rate of a reaction?

Answer 1

The change in concentration of a reactant or product per unit time.

Question 2

What is the order with respect to a reactant?

Answer 2

The power to which the concentration of a reactant is raised in the rate equation.

Question 3

What is the overall order of a reaction?

Answer 3

The sum of the individual orders

Question 4

What does it mean when a reaction is zero order?

Answer 4

The rate is unaffected by changing the concentration of the reactant.

Question 5

What does it mean when a reaction is first order?

Answer 5

The rate is directly proportional to the concentration of the reactant.

Question 6

What does it mean when a reaction is second order?

Answer 6

The change in rate will be equal to the change in concentration squared.

Question 7

What is the half life of a reactant?

Answer 7

The time taken for the concentration of the reactant to reduce by half.

Question 8

What does the concentration-time graph look like for a zero order reaction?

Answer 8

It will be a straight line with the concentration decreasing at a constant rate.

Question 9

What does the concentration-time graph look like for a first order reaction?

Answer 9

It will be a curved line with a constant half life, halving the concentration at equal time periods.

Question 10

What does the concentration-time graph look like for a zero order reaction?

Answer 10

It will be a straight line with no gradient.

Question 11

What does the concentration-time graph look like for a first order reaction?

Answer 11

It will be a straight line through the origin.

Question 12

What is a reaction mechanism?

Answer 12

A series of steps that together, make up the overall reaction.

Question 13

What is the rate determining step of a reaction?

Answer 13

The slowest step in a reaction mechanism of a multi-step reaction.

Question 14

What is an intermediate?

Answer 14

A species formed in one step of a multi-step reaction that is used up in a subsequent step and is not seen as either a reactant or a product of the overall equation.

Question 15

What is a homogeneous equilibrium?

Answer 15

An equilibrium in which all the species making up the reactants and products are in the same physical state.

Question 16

What is a heterogeneous equilibrium?

Answer 16

An equilibrium in which all the species making up the reactants and products are in different physical states.

Question 17

What is the mole fraction of a substance?

Answer 17

A measure of how much of a given substance is present in a reaction mixture,

Question 18

What is the partial pressure of a substance?

Answer 18

The pressure an individual gaseous substance would exert if occupied a whole reaction vessel on its own.

Question 19

What is a Brønsted-Lowry acid?

Answer 19

A proton donar

Question 20

What is a Brønsted-Lowry base?

Answer 20

a proton acceptor

Question 21

What is a buffer solution?

Answer 21

A mixture that minimises pH changes on addition of small amounts of acid or base.

Question 22

What is the equivalence point of a titration?

Answer 22

The point at which the volume of one solution has reached exactly with the volume of the second solution.

Question 23

What is the end point of a titration?

Answer 23

The point on a titration curve at which there are equal concentrations of the weak acid and conjugate base forms of the indicator. The colour at the end point is midway between the colours of the acid and conjugate base forms.