Chapter 6 - The Chemical Industry

Question 1

what does zero order for a reaction mean

Answer 1

• the rate is constant

- if you double the concentration it has no effect

Question 2

what does first order for a reaction mean

Answer 2

• rate = k[A]

- If you double the concentration, the rate doubles

Question 3

what does second order for a reaction mean

Answer 3

• rate = k[A]^2

- if you double the concentration, the rate quadruples

Question 4

describe how to use a colorimeter to follow rate of reactions

Answer 4

• choose a complementary filter that transmits only the frequencies absorbed by the solution in the cuvette
• reference with water/solvent to calibrate to 0
• record absorbance at regular time intervals
• plot a graph of absorbance vs time and construct line of best fit
• draw a tangent and find its gradient

Question 5

what is the half-life of a chemical reaction

Answer 5

the time it takes for the concentration of the reactant to drop to half its initial value

Question 6

what factors affect the value of Kc

Answer 6

only temperature