Acid, bases, salts (Part 1)

Which statements are properties of an acid?

1 reacts with ammonium sulfate to form ammonia

2 turns red litmus blue

• Statement 1 & 2

• Statement 1 only

• Statement 2 only

• None of the statement above

Which property is not characteristic of a base?

• It reacts with a carbonate to form carbon dioxide.

• It reacts with an acid to form a salt.

• It reacts with an ammonium salt to form ammonia.

• It turns universal indicator paper blue.

A sting from insect X has a pH of 6 and a sting from insect Y has a pH of 8. The table shows the pH of four substances

Which substances are used to treat the two stings?

• X: hydrochloric acid; Y: sodium hydroxide

• X: sodium hydrogen carbonate; Y: vinegar

• X: sodium hydroxide; Y: hydrochloric acid

• X: Vinegar; Y: sodium hydrogen carbonate

The table shows the pH of four aqueous solutions, W, X, Y and Z. Universal Indicator is added to each solution. Which row shows the colour of each solution after the indicator is added?

• W: blue, X: green, Orange, Z: red

• W: green, X: blue, Y: red, Z: orange

• W: orange, X: red, Y: blue, Z: green

• W: red, X: orange, Y: green, Z: blue

Hydrochloric acid is used to clean metals. The acid reacts with the oxide layer on the surface of the metal, forming a salt and water. Which word describes the metal oxide?

• alloy

• base

• element

• indicator

Which statement is not correct?

• When a base reacts with an ammonium salt, ammonia is given off.

• When an acid reacts with a base, neutralisation takes place.

• When an acid reacts with a carbonate, carbon dioxide is given off.

• When the acidity of a solution increases, the pH increases.

Which reaction is not characteristic of an acid?

• It dissolves magnesium oxide.

• It produces ammonia from ammonium compounds

• It produces carbon dioxide from a carbonate.

• It produces hydrogen from zinc metal.

Which equation for the reaction between sodium carbonate and dilute hydrochloric acid is correct?

• Na₂CO₃(s) + HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + HCl(aq) → Na₂Cl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + CO₂(g) + H₂O(I)

Some reactions of a substance, R, are shown in the diagram.

What type of substance is R?

• an acid

• a base

• an element

• a salt

Which statements about alkalis are correct?

1 When reacted with an acid, the pH of the alkali increases. 2 When tested with litmus, the litmus turns blue.

3 When warmed with an ammonium salt, ammonia gas is given off.

• 1, 2 and 3

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only