For question 17, thanks

a) Zinc react with hydrochloric acid, it produces zinc chloride which is present in aqueous solution and hydrogen gas.

b) When calcium chloride react with sodium carbonate, it produces calcium carbonate (solid) and sodium chloride (liquid).

c) Sodium hydroxide react with hydrochloric acid, it produces sodium chloride (liquid) and water.

d) When calcium carbonate decompose, it forms calcium oxide which is present in solid form and carbondioxide gas.

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.