exam stuff

Question 1

chem equation for ammonia reacting with sulfuric acid

Answer 1

2NH3 + H2SO4 → (NH4)2SO4

Question 2

how to test if iodine or chlorine is more reactive with chlorine solution and sodium iodide

Answer 2

M1 add chlorine (solution) to sodium iodide (solution)
M2 solution turns brown
M3 iodine/I2 is displaced
formed
M4 (so) chlorine is more reactive (than iodine) ORA

Question 3

Give the catalyst and temperature used in the industrial process to convert
long‑chain molecules into shorter‑chain molecules

Answer 3

silica and 600-700

Question 4

rust

Answer 4

iron 111 oxide

Question 5

Explain why calcium bromide has a much higher melting point than caffeine.

Answer 5

M1 calcium bromide is a giant (ionic)
lattice/structure

M2 with many/strong electrostatic attractions
between (oppositely charged) ions

M3 caffeine has a simple molecular structure

M4 caffeine has weak intermolecular forces
/weak forces between molecules

M5 more energy is needed to break the
electrostatic attractions (in calcium bromide)
than to overcome the intermolecular forces (in
caffeine)

Question 6

reaction of nitrogen dioxide and water and oxygen to make nitric acid

Answer 6

4NO2 + 2H2O + O2 → 4HNO3