PAPER 1 - PRACTICALS

Question 1

method of energy changes practical - 8 steps

Answer 1

1. add acid to polystyrene cup
2. record start temp of solution with thermometer in a hole in the solution
3. add the other reactant to the cup
4. add a lid and stir the soltuion
5. record the highest/lowest temp
6. calulate the temp change
7. repeat steps to find anomalies and mean
8. repeat steps 1-7 with different test solutions (the thing you add to the acid)

Question 2

what is the polystyrene cup practical used to measure

Answer 2

energy changes

Question 3

what equipment do you need for the energy change practical

Answer 3

polystyrene cup - good insulator that reduces energy transfer to the surroundings
lid with hole - reduces energy transfer to surroundings
thermometer - measure temperature
balance - measure mass
measuring cylinder - volume
stick to stir

Question 4

what different reactants could be used when doing the temp change practical

Answer 4

• acid and metal
• acid and metal carbonate
• neutralisation reaction - acid and base
• displacement reaction - reactive metal and non reactive

Question 5

how would you use the energy change practical to find the reactivity of a metal

Answer 5

• investigate the temp change
• more reactive metal - greater temp change

Question 6

whats the titration practical used to measure

Answer 6

the volume of an acid or alkali that would neutralise an unknown acid or alkali

Question 7

method of titration - 8 steps

Answer 7

1. add acid/base to conical flask - known volume with PIPETTE
2. add indicator to conical flask and swirl to mix
3. stand flask on white tile
4. fill burette with acid/base - you dont know how much so j fill with loads but record this volume
5. add drops of acid/base in burette and swirl everytime
6. stop when colour change
7. measure the volume of the burette and find the difference - this is how much it took to neutralise
8. repeat

Question 8

what questions have been asked in the past with titration

Answer 8

• what v of citric acid need to neutralise sodium hydroxide
• what v of sulphuric acid need to neutralise sodium hydroxide
• what v of sodium hydroxide need to neutralise rainwater
  HYDROXIDE - ALKALI
  ACID - ACIDIC
  RAIN WATER - ACIDIC

Question 9

for titration - which acid/base goes in the burette and which goes in the conical flask

Answer 9

KNOWN volume — CONICAL FLASK
UNKNOWN volume — BURETTE

Question 10

what colour is phenolphthalein in acid/alkali

Answer 10

colourless - acid
pink - alkali