11A.1

Question 1

what is the rate of reaction

Answer 1

it is the change of species ( atom, ion, or molecule taking part in a chemical reaction) concentration divided by the time taken for the change to occur.

Question 2

what’s the formula to calculate the rate
of
reaction

Answer 2

(change of concentration in the product)/ time or –
- (change of concentration in reactant)/ time

Question 3

all rate of reactions values are

Answer 3

positive

Question 4

what is the SI for the rate of reaction

Answer 4

mol dm^-3 s^-

Question 5

what are the techniques to measure the rate of reaction

Answer 5

1. measuring the volume of the gas evolved
2. measuring the change of mass of a reaction
3. monitoring the colour change (calorimetry)
4. analysis by titration
5. measuring by electrical conductivity
6. measuring any other physical property that shows a significant change

Question 6

choosing the technique to measure the rate of reaction depends on

Answer 6

1. the nature of the reactants and products (state)
2. the conditions the reaction was carried under

Question 7

what are the techniques used to measure the volume of the gas, and which is better (ur mom)

Answer 7

1. collecting it over water into a measuring cylinder
2. collection using a gas syringe

(gas syringe has more precision) not the ones we have thou

Question 8

what gases can not be used in gas collection over water

Answer 8

gases that are soluble in water such as sulfur dioxide

Question 9

what are the two techniques that could be used to measure the rate of reaction when gas is a product forming

Answer 9

1. measuring the volume of the gas evolved
2. measuring the change of mass of a reaction

Question 10

what’s the problem with measuring the change of mass of a reaction when gas is involved

Answer 10

gas with low density (low Mr) produces such small mass changes that measurement uncertainties become significant

Question 11

monitoring the colour change

Answer 11

by using colorimetry to detect more subtle changes in colour

Question 12

whats are taking small samples using a pipette called

Answer 12

the samples are called aliquots

Question 13

how is titration used to determine the rate of reaction

Answer 13

you would take out aliquots from a reaction mixture and then either stop the reaction going on by adding another substance or by slowing it down almost to zero by putting it in an ice bath and then titrate it with a substance that can help you determine the concentration of the reactant/product for ex (acid would be titrated by a base)

Question 14

whats is quenching

Answer 14

the process that stops or slows down the reaction in an aliquot

Question 15

how can we follow the electrical conductivity in a reaction mixture, and why is it possible to do that

Answer 15

a conductivity meter, because during a reaction the number of ions or the type can change

Question 16

what are other physical quantities that could show a significant change

Answer 16

1. the change in the volume of liquid (dilatometry)
2. chirality
3. refractive index