Understanding Mixtures and Compounds

What is the initial step in preparing Mixture A?

• Mix sulphur powder and iron filings in a beaker.

• Dissolve sulphur in carbon disulphide.

• Heat sulphur powder in a china dish.

• Add iron filings to a beaker.

What is observed when Mixture A is stirred in a watch glass?

• The mixture turns into a liquid.

• Yellow powder with visible iron filings is seen.

• A homogeneous black mass is formed.

• No visible change occurs.

How does Black mass B appear when stirred?

• It turns into a liquid.

• Iron filings are visible.

• It appears as a yellow powder.

• No iron filings are visible.

What happens when a magnet is brought near Mixture A?

• No change is observed.

• The mixture turns black.

• Iron filings cling to the magnet.

• The magnet repels the mixture.

What is the behavior of Black mass B towards a magnet?

• The mass turns into a liquid.

• Iron filings cling to the magnet.

• No particles attach to the magnet.

• The magnet repels the mass.

What happens when carbon disulphide is added to Mixture A?

• The mixture turns black.

• The mixture becomes homogeneous.

• Sulphur dissolves and reappears.

• No change is observed.

What is observed when carbon disulphide is added to Black mass B?

• Sulphur dissolves and reappears.

• The mass turns into a liquid.

• No change is observed.

• The mass becomes heterogeneous.

What gas is evolved when Mixture A is heated with dilute HCl?

• Oxygen

• Carbon dioxide

• Nitrogen

• Hydrogen

What gas is produced when Black mass B reacts with dilute HCl?

• Hydrogen

• Oxygen

• Hydrogen sulphide

• Carbon monoxide

What is the result of heating Black mass B?

• It turns into a liquid.

• It reacts with air.

• No change is observed.

• It becomes a yellow powder.