EQUATIONS

Question 1

When testing for halide ions, give the equation for when nitric acid removes other ions such as carbonates

Answer 1

CO3 2- + 2H+ -> CO2 + H2O

Question 2

Give the general equation for when sodium halide reacts with H2SO4 in an acid base reaction

Answer 2

NaX + H2SO4 -> NaHSO4 + HX

Question 3

Give the equation from when either AgCl or AgBr react with conc. ammonia

Answer 3

AgX(s) + 2NH3(aq) -> [Ag(NH3)2]+(aq) + X- (aq)

Question 4

Give the equation for when bromide ions react with H2SO4 in a redox reaction

Answer 4

2HBr + H2SO4 -> SO2 + Br2 + 2H2O

Question 5

Giv the overall redox equation when iodide ions react with H2SO4 to produce a choking gas

Answer 5

2I- + 2H+ + H2SO4 -> 2H2O + 2I2 + SO2

Question 6

Give the overall redox equation when iodide ions react with H2SO4 to produce a bad egg smell

Answer 6

8I- + 8H+ + H2SO4 -> 4I2 + H2S + 4H2O

Question 7

Give the overall redox equation when iodide ions react with H2SO4 to produce

Answer 7

6I- + 6H+ + H2SO4 -> 3I2 + 3H2O + S

Question 8

Give the equations for the contact process. What type of catalyst is used?

Answer 8

Heterogenous catalyst

V2O5 + SO2 -> SO3 + V2O4-
V2O4- + 1/2O2 -> V2O5

Question 9

Give an equation for when an auto catalyst can be used in a titration. What type of catalyst is this? What is seen during the reaction?

Answer 9

Homogenous catalyst

2MnO4- + 5C2O4 2- + 16H+ -> 2Mn2+ + 10CO2 + 8H2O

4Mn2+ + MnO4- + 8H+ -> 4H2O + 5Mn3+

2Mn3+ + C2O4 2- -> 2CO2 + 2Mn2+

Pink to colourless soliton

Question 10

Give the equation for the harder process, what catalyst is used and what type of catalyst is it?

Answer 10

Fe (s)- heterogenous catalyst

N2 (g) + 3H2 (g) <-> 2NH3

Question 11

Give an example of when Fe can be used as a homogenous catalyst, why is the catalyst needed in this reaction?

Answer 11

Overall equation:
S2O8 2- + 2I- -> I2 + 2SO4 2-
Two negatives repel, so the activation energy is very high, therefore catalyst required

S2O8 2- + 2Fe2+ -> 2SO4 2- + 2Fe3+
2Fe3+ + 2I- -> I2 + 2Fe2+