Acids, bases and salts

Question 1

What is meant by the term acid? [1]

Answer 1

proton donor

Question 2

Give 2 observations when HCL reacts with magnesium [2]

Answer 2

fizzing
solid dissolves

Question 3

State 2 observationsn which shows that HCL is stronger acid than ethanoic acid when added to calcium carbonate [2]

Answer 3

faster rate of fizzing
solid dissolves quicker
fizzing stop quicker

Question 4

Complete equation
Mg+CH2(COOH)2->

Answer 4

MgCH2(COO)2+H2

Question 5

What difficulty arises if the name of a compound of a transition element does not include its oxidation state, such as iron oxide? [2]

Answer 5

they have more than one oxidation state/valency
there are 2 iron oxides

Question 6

Describe how you could show that ethylamine is a weak base like ammonia and not a strong base like sodium hydroxide [3]

Answer 6

equal conc of both solutions
add universal indicator
ethylamine lower ph
OR
equal conc of both solutions
measure conductivity of aq solution of both
ethylamine lower conductivity

Question 7

Suggest how you could displace ethylamine from salt ethylammonium chloride [2]

Answer 7

add stronger base
warm/heat

Question 8

Explain: when aq ethylamine is added to aq iron (III) chloride, a brown precipitate is formed [2]

Answer 8

ethylamine forms hydroxide ions in water
react w/ iron (III) ions

Question 9

Describe how you could show that aluminium oxide is an amphoteric oxide [3]

Answer 9

name/formula of strong acid and alkali
reacts w/ /neutralises w/ both acid and alkali
dissolves in both

Question 10

Deduce why 2 acids must have different conc for fair comparison of acidity [1]

Answer 10

so same conc of H+ ions

Question 11

Predict one physical property of rubidium which is the same as that of a transition element such as iron [1]

Answer 11

conducts electricity

Question 12

Predict 2 physical properties of rubidium which are different to those of a transition element such as iron [2]

Answer 12

low mp and bp
rubidium softer

Question 13

Sodium chloride is solid, dissolves in water to give neutral solution. Phosphorus trichloride is liquid at room temp, reacts with water to form acidic solution, explain differences [3]

Answer 13

sodium chloride ionic, PCl3 covalent
ionice bonds strong, intermolecular forces weak
Pcl3 reacts with water, NaCl does not

Question 14

Usually for metal and reactant observations say the metal dissolves

Question 15

Define precipitate [2]

Answer 15

a solid
which forms when 2 solutions are mixed

Question 16

Magnesium chloride carbonate added to excess HCL. FIltered and residue washed. Why wash? [1]

Answer 16

make sure all salt goes through

Question 17

Describe the test for sulfur dioxide [2]

Answer 17

add to potassium manganate (VII)
purple to colourless

Question 18

Aq silver nitrate produes a yellow precipitate with both iodide ions and carbonate ions. When testing an unknown solution for iodide ions, the aqueous silver nitrate is acidified. Explain why aq silver nitrate is acidified [1]

Answer 18

nitric acid reacts with carbonate ions