Mole Concept And Stoichiometry — Chemistry STD 10 — Question

Determine the  molecular mass of a gas if 5g of it occupy a volume of 4 L at STP.

A white solid A when heated with sodium hydroxide solution, gives a pungent gas B, which turns red litmus blue. The solid, when dissolved in dilute nitric acid and treated with silver nitrate gives a white precipitate of C which is soluble in an ammonia solution.

In the third period, which is the most metallic and most non-metallic element?

What wilI you observed when concentrated HCI is added to lead (IV) oxide and warmed ?

Give appropriate scientific reasons for the following statement :
Electrolysis of molten lead bromide is considered to be a redox reaction.

State the observation at the anode and at the cathode during the electrolysis of :
Copper sulphate solution using copper electrodes.

Answer the following questions with respect to the electrolytic process in the extraction of aluminium:
(i) Identify the components of the electrolyte other than pure alumina and the role played by each.
(ii) Explain why powdered coke is sprinkled over the electrolytic mixture.

What is an alloy? Give three reasons why alloys are made.

Explain the following:
Aqueous ammonia conducts electricity.