Chemical Bonding — Chemistry STD 10 — Question

In a chemistry lab, a student is given a solution containing an unknown cation. The student adds sodium hydroxide (NaOH) to the solution and observes the formation of a blue precipitate. The student then decides to add ammonium hydroxide to a fresh sample of the solution in excess.
(a) Identify the cation.
(b) What happens when excess of NaOH is added in the solution?
(c) What happens when excess of ammonium hydroxide is added to the solution?

What is the formula for liquid ammonia? Account for the basic nature of this compound.

Use the information given in (a) to (h) to identify the substances P to W selecting your answers from the given list.
List:

Calcium	Oxygen	Copper (II) Oxide
Carbon	Calcium hydroxide	Copper (II) Nitrate
Lead (II) Oxide	Hydrogen chloride	Chlorine
Lead (II) Nitrate	Calcium Oxide	Ammonium chloride

(a) P is white solid. When heated produces white fumes (sublime).
(b) P and R on warming produce an alkaline gas.
(c) On adding water to T, heat is evolved and R is formed.
(d) Q burns brightly in the air to form T.
(e) When S is heated, it gives off brown fumes and leaves a black residue of U.
(f) A solution of S is formed by warming U with dilute nitric acid.
(g) V is a gaseous non-metallic element that reacts with hydrogen to form W.
(h) A solution of W will neutralize the solution of R.

Mention three important uses of nitric acid; Give the property of nitric acid involved in the use.

Which concentrated acid oxidizes sulphur directly to sulphuric acid ? Write the equation for the same. What is the name of the process by which sulphuric acid is manufactured ? Name the catalyst used in the process.

Calculate the number of gram atoms in 4.6 gram of sodium

Give two chemical tests for nitric acid.

With the help of equations, give an outline for the manufacture of sulphuric acid by the contact process.

Define a coordinate bond and give the conditions for its formation.