When pollen grains are placed in water in a trough and observed under a microscope, the grain particles will be seen to
all remain stationary
all move randomly
Stick together in a cluster
all move in one direction.
Which one of the following does not involve a change in mass when heated in air?
Potassium permanganate
Copper (II) hydroxide
Zinc oxide
Copper
Which one of the following properties is not true about oxygen gas?
It is colorless
It is neutral
It is odorless
It is a reducing agent
Which one of the following is NOT a characteristic of metals?
Conduct electricity
Conduct heat.
Their atoms form cations.
Their atoms form anions
Which one of the following statements is false about the kinetic theory of gases?
Gas molecules consist of tiny particles.
Gas particles collide with one another.
Gas particles are in a state of continuous motion.
There are large forces of attraction between gas particles.
Which pair of the mixtures below can be separated by sublimation?
Sodium chloride and lead (II) chloride.
Copper (II) chloride and zinc nitrate.
Zinc sulphate and lead (II) nitrate.
Ammonium chloride and zinc chloride,
The most efficient method for separating a mixture of copper (II) sulphate and lead (II) sulphate is by dissolution followed by
decantation.
sublimation,
filtration.
crystallization.
The process of making steel from iron is called
galvanization.
metal plating.
glazing.
alloying.
The substance that will not sublime when heated is
sulphur.
ammonium chloride
iron (III) chloride.
iodine.
Metal P displaces hydrogen from a dilute acid but metal Q does not. Metal R displaces P from its chloride. The order of reactivity of the metals beginning with the most reactive is
P, Q, R
Q, P, R
R, Q, P
R, P, Q
A separating funnel is used in the laboratory to separate
Sand from water
Sulphur from Iron
Water from ethanol
Water from paraffin
Air contains mainly
Carbon dioxide
Oxygen
Nitrogen
Water vapour
Which one of the following pairs of substances will react to form hydrogen?
copper and dilute sulphuric acid
magnesium and dilute hydrochloric acid
copper (II) carbonate and dilute sulphuric acid
sodium sulphite and dilute hydrochloric acid
Which one of the following mixtures can be separated by filtration?
sugar and water
ink and water
Sulphur and iron
Sand and salt
When a solid is heated it changed to gas without passing through the liquid state. This change of state is called
Evaporation
distillation
Condensation
sublimation
Which one of the following are the raw materials used to manufacture hydrogen gas on a large scale?
Zinc and dilute sulphuric acid
Iron and water
Carbon and water
Calcium and water
Which one of the following substances is deliquescent?
calcium hydroxide
sodium hydroxide
magnesium hydroxide
zinc hydroxide
. Which one of the following processes decreases the concentration of carbon dioxide in the atmosphere?