21.

Why does covalent compound exist as gases, liquid or soft solid?

c) Name the kind of particles solution:

i) sodium hydroxide solution

ii) carbonic acid

iii) sugar solution

An element Z has atomic number 16. Answer the following question on Z: 

i) State the period and group to which Z belongs. 

ii) is Z a metal or non-metal?

iii) State the formula between Z and Hydrogen.

iv) What kind of a compound is this? 

Draw the structure of the stable positive ion formed when an acid dissolves in water.

State the inference drawn from the following observations:

(iii) pH of liquid R is 10. What kind of substance is R?

(iv) Salt S is prepared by reacting dilute sulphuric acid wit copper oxide. Identify S.

Give balanced chemical equations to prepare the following salts:

Lead sulphate from lead carbonate.

Give balanced chemical equations to prepare the following salts:

Sodium sulphate using dilute sulphuric acid.

Give balanced chemical equations to prepare the following salts:
Copper chloride using copper carbonate.

Distinguish between the following pairs of compound using the test given within brackets:

Iron(II) sulphate and iron(III) sulphate (using ammonium hydroxide)

State your observation in the following case:

When excess sodium hydroxide is added to calcium nitrate solution.