ACIDS, BASES AND SALTS

Select the properties of acids:

• turns blue litmus red

• corrosive

• soluble in water

• proton acceptor

Bases are _________ or _________ of metals

(a)  

TRUE OR FALSE: Alkalis are a sub group in the large family of bases.

• false

• true

Calcium hydroxide is a well known ​ (a)   with low ​ (b)   in water unlike other ​ (c)  

• base
• solubility
• alkalis

Match the following

• in acids - colourless and alkalis - blue

• methyl orange

• in acids - red and alkalis - yellow

• thymolphthalein

• in acids - red and alkalis - blue

• litmus

solutions of acids x and y have the same concentrations. X has pH 2.5. Y has pH 5.3. Which one is a weak acid, explain your reasoning:

Answer explanation

Acid Y is the weaker acid as it has a pH of 5.3 , the higher pH number for acids, the weaker they are as the do not fully dissociate in solution or have a reversible reaction for their dissolution:

Eg: acetic acid CH3COOH, dissociates in solution as follows:

CH₃COOH --------------->

<-------------- CH₃COO^- + H⁺

Metal + acid -----------> _________ + ________

(a)  

Acid + base -------> _______ + _________

(a)  

Name the products of the following reaction:

Calcium carbonate + Hydrochloric acid

• calcium chloride + water

• calcium carbonate + carbon dioxide

• calcium chloride + hydrogen

• calcium chloride + carbon dioxide + water

A compound X on reaction with a test tube of copper (II) oxide produced a blue coloured solution, releasing a colourless gas which puts out a burning splint with a pop sound. Identify the compound:

• salt

• base

• acid

• alkali