3) Chemistry in Society

Question 1

Reminder: make sure a redox equation has no spectator ions

Answer 1

a redox equation has no spectator ions

Question 2

how to prepare stock solution

Answer 2

rinsings of the container the stock solution is made in is added to the standard solution. it is dissolved in a beaker then transferred

Question 3

two ways to ensure an accurate endpoint

Answer 3

• repeat for concordency

- use a white tile so you can see the colour change easier

Question 4

for a reaction at equilibrium, after two more hours of that reaction continuing is the rate of the forward and backward reaction increased/decreased/unchanged for each way

Answer 4

unchanged for both

Question 5

what does a pipette do

Answer 5

accurately measures an exact volume of a liquid

Question 6

what does a burette do

Answer 6

accurately measures out variable volumes of liquid

Question 7

what is a standard solution

Answer 7

a solution of accurately known concentration

Question 8

two reasons why some solids are unsuitable for making a standard solution

Answer 8

not pure//not completely dry//insoluble

Question 9

How to prepare a standard solution (5 steps)

Answer 9

1) using a beaker accurately measure out the mass of substance required
2) stirring, add distilled water to dissolve the substance completely
3) pour solution into a flask, using a wash bottle to rinse out any remaining substance from the beaker and stirring rod
4) add distilled water to just below the line on the flask
5) using a dropping pipette add more water until the bottom of the meniscus is on the mark on the flask

Question 10

how do you make a standard solution of very low concentration (easiest way)

Answer 10

dilute a solution of higher concentration

Question 11

a solution is more accurately measured using a pipette/burette

Answer 11

burette

Question 12

Reminder: gas syringe almost always works for collection of gases both more and less dense than air

Answer 12

gas syringe almost always works for collection of gases both more and less dense than air

Question 13

At equilibrium catalysts _____ the activation energy of the forward and/or backward reactions

Answer 13

At equilibrium catalysts decrease the activation energy of the forward reaction

Question 14

At equilibrium are the energies of the forward and backward reactions equal?

Answer 14

At equilibrium are the energies of the forward and backward reactions are NOT EQUAL

Question 15

What effect do catalysts have on the backward reaction at equilibrium

Answer 15

Catalysts do not have an effect on the backward reaction at equilibrium

Question 16

What effect do catalysts have on both the forward and backward reactions

Answer 16

increase both the forward and backward reactions

Question 17

What effect do catalysts have on the forward reaction at equilibrium

Answer 17

Catalysts do not have an effect on the forward reaction at equilibrium

Question 18

the molar volume does/doesn’t change depending on what elements are present

Answer 18

the molar volume doesn’t change depending on what elements are present

Question 19

the substance that is NOT in excess is the ___________

Answer 19

the substance that is NOT in excess is the limiting factor and that is used for calculation

Question 20

conditions for the haber process

Answer 20

moderate temperature and pressure is used

Question 21

does the process of ionisation have a positive of negative enthlapy change and is exo/endo thermic

Answer 21

positive enthlapy change and is exothermic

Question 22

does the process of an element gaining electrons have a positive of negative enthlapy change and is exo/endo thermic

Answer 22

negative enthlapy change and is endothermic

Question 23

REMINDER: when a q asks you to draw or choose an isomer of a given molecule - do not choose or draw the given molecule exactly

Answer 23

REMINDER: when a q asks you to draw or choose an isomer of a given molecule - do not choose or draw the given molecule exactly