Acid, Bases and Salt

The pH values of four aqueous solutions are shown. 

    Which solution contains a weak acid?

• pH 2

• pH 5

• pH 7

• pH 9

Which type of reaction takes place when H⁺ ions and OH^- ions react to form water?

• condensation

• ionisation

• neutralisation

• precipitation

Aluminium chloride dissolves in water to form a solution with a pH less than 7. Which ion in the solution makes the solution have a pH less than 7?

• aluminium

• chloride

• hydrogen

• hydroxide

The approximate pH values of the aqueous solutions of four substances commonly used in cooking are shown. 

    Which substance could be taken to neutralise excess acid in the stomach?

• Baking soda, pH 9

• Salt, pH 7

• Lemon juice, pH 4

• Vinegar, pH 3

Which statement about all acids is correct?

• They contain both hydrogen and oxygen.

• They give ammonia with an ammonium salt.

• They have a pH value below 7.

• They react with all metals to form hydrogen.

Ammonia may be obtained from ammonium chloride by heating with.......

• Aqueous calcium chloride.

• Aqueous sodium hydroxide.

• Dilute hydrochloric acid.

• Water.

The table shows the pH value of 5 soil samples. Cabbages grow best in alkaline soil.

     In which of the soil samples should cabbage grow well?

• P and Q

• Q and T

• R and P

• S and T

Tags

NGSS.MS-LS1-5

Sodium hydroxide is an alkali. 

      Which statement about aqueous strontium hydroxide is correct?

• The solution contains fewer hydrogen ions than hydroxide ions.

• The solution has a pH less than 7.

• The solution reacts with metal carbonates to form carbon dioxide.

• The solution turns blue litmus red

The oxide of a metal reacts both with hydrochloric acid and with aqueous sodium

      hydroxide. The type of oxide is.....

• acidic.

• amphoteric.

• basic.

• neutral.

Which compound is an amphoteric oxide?

• Calcium oxide

• Copper (II) oxide

• Sulphur dioxide

• Zinc oxide