C1 2021

Question 1

In born haber cycles if theres 2Cl + 2e- to 2Cl- what do you do

Answer 1

Multiply enthalpy change by 2

Question 2

Magnesium chloride dissolved in water
Give an equation inc state symbols to represent the process that occurs when the enthalpy of solution of magnesium chloride is measured

Answer 2

MgCl2 (s) -> Mg2+ (aq) + 2Cl- (aq)

Question 3

When calculating enthalpy of solution and theres hydration of Cl2/Br2 what do you do

Answer 3

Mulitply enthalpy change by 2

Question 4

An element in period 3 forms an oxide that is insoluble in water
This oxide reacts with sulfuric acid and with aq KOH
Give formula for this oxide and write equation for this oxide with sulfuric acid

Answer 4

Al2O3
Al2O3 + 6H+ -> 2Al3+ + 3H2O

Question 5

Give formula of a hydroxide of an element in period 3 used in medicine

Answer 5

Mg(OH)2

Question 6

What factors affect the effiecncy and lifetime of the catalyst

Answer 6

Large SA using powdered
Catalyst poisoned
Active sites blocked

Question 7

Explain why the value of kw increases as temp increases

Answer 7

Reaction is endothermic
Equilibrium shifts to the right to oppose increase in temp

Question 8

Explain why the volume of NaOH sol added between each pH measurement is smaller as the end point of the titration is approached

Answer 8

To avoid missing end point

Question 9

State the temp at which the standard entropy of aluminium is 0JKmol-1

Answer 9

0k

Question 10

Suggest why the two colbolt (lll) complex ions in table 8 have different electrode potentials

Answer 10

Different ligands