Chemistry in society

Question 1

Chromatography is ..

Answer 1

The term used to describe a technique which is used to separate and identify substances in a mixture

Question 2

In what order do carbon compounds move through the paper quickest. Quickest to slowest

Answer 2

Saturated hydrocarbons
Unsaturated hydrocarbons
Esters
Ketones
Aldehydes
Alcohols

Question 3

Most polar substances will be ….

Answer 3

Moved the slowest

Question 4

What is the time taken for a substance to be known as?

Answer 4

The retention time

Question 5

Standard solution definition

Answer 5

A solution of accurately known concentration

Question 6

what does dynamic equilibrium mean?

Answer 6

that the rate of forward and reverse reactions are equal

Question 7

The enthalpy of combustion of a substance….

Answer 7

Is the amount of energy given out when one mole of a substance burns completely with oxygen

Question 8

what is volumetric analysis used to determine

Answer 8

the exact concentration of another substance using titration

Question 9

state what titration is

Answer 9

its used to determine the volume of solution to reach the end-point of a reaction

Question 10

state what is a standard solution

Answer 10

a solution with an accurately known concentration

Question 11

how do you make up a standard solution

Answer 11

1. accurately weigh a know mass of material using a 3.d.p balance
2. transfer the material from the weigh boat to a clean dry beaker
3. add deionised water to the beaker to de-solve it
4. use a funnel to ensure no loss of the solution and pour the solution into a dry volumetric flask and rise the beaker 3X down with deionised water and add it to the flask
5. fill the flask up to almost the line and put a stopper on an shake to mix
6. take the stopper out and fill the volume up to the mark
7. put the stopper back in and shake to mix the standard solution

Question 12

factors effecting industrial process

Answer 12

availability
product yield
marketability
recycling
energy requirements
reducing waste
using less toxic chemicals
biodegradable products

Question 13

3 ways to change the position of equilibrium

Answer 13

concentration, pressure, temperature

Question 14

what happens if you change the concentration in the reaction

Answer 14

increasing shifts it to the right, more product
decrease shifts it Ito the left, products forms more reactants

Question 15

what happens if you change the pressure in the reaction

Answer 15

increasing causes the equilibrium to the direction where there are fewer moles gas
decrease causes the equilibrium to the direction with more moles of gas
if there is the same moles of gas of each side there is no change on the equilibrium

Question 16

what happens if you change the temperature in the reaction

Answer 16

increase favours the endothermic reaction
decrease favours the exothermic reaction

Question 17

what effect does a catalyst have on equilibrium

Answer 17

it helps to reach equilibrium faster but has on effect on the position of equilibrium

Question 18

what is chromatography

Answer 18

its the set of techniques which can be used to separate and identify substances in a mixture

Question 19

what is a negative impact to industry if reaction rate is too slow

Answer 19

reduced profit

Question 20

what is negative impact on industry if reaction rate is too fast

Answer 20

runaway reactions

Question 21

define an activated complex

Answer 21

an unstable complex intermediate molecule

Question 22

what is a homogenous catalyst

Answer 22

same state as the reactants

Question 23

what is a heterogeneous catalyst

Answer 23

different state to the reactants

Question 24

what is temperature a measurement of

Answer 24

average kinetic energy

Question 25

hess’s law states

Answer 25

the overall energy change is any given reaction is independant to the route taken