U2 exam revision

Question 1

Amphiprotic substances

Answer 1

HCO3-, H2O, HSO4-, H2PO4–, HPO42–

Question 2

The concentration of ions in the solution is …..

(trend)

Answer 2

inversely proportional to the amount of light detected by the detector

Question 3

Darker solution indicates …

in light spectrometry

Answer 3

= more light absorbed

Question 4

polarity

Answer 4

imbalance/difference in charge on either side

Question 5

Why filtration in gravimetric analysis?

Answer 5

To get rid of spectator ions that might have been mixed with precipitate

Question 6

Assumptions in gravimetric analysis:

Answer 6

no errors occured, all sulphate was precipitated, none was lost

Question 7

Improve reliability of gravimetric analysis:

Answer 7

repeat, add excess, dry thoroughly

Question 8

Cathode carries what charge?

Answer 8

carries positive charge

Question 9

which direction do electrons move through the salt bridge?

Answer 9

Anions move from anode to cathode

Question 10

Strong acid

Answer 10

readily donates proton to water

Question 11

What is the purpose of washing in gravimetric analysis?

Answer 11

Some precipitate sticks to sides of beaker, wahsing = all precipitate on filter paper

Question 12

Gravimetric analysis: why wasn’t the yield 100%?

Answer 12

Some precipitate was lost, some may not have reacted

Question 13

Why dilution in spectrometry?

Answer 13

To ensure the absorbance value fits calibration curve

Question 14

Species that can act as both an odidising and reducing agent:

Answer 14

Fe2+ H2O, MnO2

Question 16

horizontal parts on a phase graph of latent heat

Answer 16

contain a mixture of ice and water or water and steam

Question 17

How does SHC allow the seasons to change slowly?

Answer 17

oceans absorb and release heat slowly as it takes a large amount to raise the temperature = climate gradually changes

Question 18

In a redox reaction, would the solid metal increase in mass?

Answer 18

Depends on molar mass of the metal

Question 19

How does zinc prevent the rusting of iron?

Answer 19

As it preferentially oxidises over iron

Question 20

Why does the thickness of zinc in galvanised objects decrease over time?

Answer 20

Zinc ions washed away, zinc mass decreases

Question 21

pH of water

Answer 21

always neutral, H3O+ is equal to OH-

Question 22

Advantage of reducing volume of solution before gravimetric analysis.

Answer 22

less time to filter

Question 23

Use of water that depends on SHC

Answer 23

coolant in car radiator