In a water body, too much sewage leads to
A decrease in the temperature of the water which causes death of aquatic animals
An increase in the number of aquatic animals in the water
An increase in the bacterial population which reduces the level of oxygen in the water
A decrease in the bacterial population which increases the level of oxygen in the water
10.0 dm3 of water was added to 2.0 mol dm−3 of a 2.5 dm3 solution of HCl. What is the concentration of the final solution (mol dm−3)?
0.4
8.0
2.0
0.5
Three drops of a 1.0 mol dm−3 solution of HCl were added to 20 cm3 of a solution of pH 6.4. The pH of the resulting solution will be
Close to that of pure water
Less than 6.4
Greater than 6.4
Unaltered
Which of the following substances is not a salt?
Aluminium oxide
Sodium hydrogen trioxosulphate(V)
Sodium trioxocarbonate(V)
Zinc chloride
An insoluble salt can be prepared by
The reaction of trioxocarbonate(V) with an acid
Double decomposition
The action of dilute acid on an insoluble base
The reaction of metals with an acid
