Question

Q1- Give the names of the elements present in the follow
(e)
Calcium
compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate.

Q2- Calculate the molar mass of the following substances,
(a) Ethyne, C,H,
(b) Sulphur molecule, Sg
(c) Phosphorus molecule, P. (Atomic mass of phosphoru
= 31)
(d) Hydrochloric acid, HCI
(e) Nitric acid, HNO,

Q3- What is the mass of
(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms (Atomic mass of aluminium
= 27)?
(c) 10 moles of sodium sulphite (Na, SO)?

Q4-Convert into mole.
12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.

Q5- What is the mass of:
(a) 0.2 mole of oxygen atoms?
(b) 0.5 mole of water molecules?

Q6- Calculate the number of molecules of sulphur (Se) present in
16 g of solid sulphur.

Q7-Calculate the number of aluminium ions present in 0.051 g
of aluminium oxide.
(Hint: The mass of an ion is the same as that of an atom of
the same element. Atomic mass of Al = 27 u)
​

Answer 1

Answer:

In quick lime, calcium and oxygen is present. In hydrogen bromide, hydrogen and bromine is present. In baking powder, sodium, hydrogen, carbon and oxygen is present and in potassium sulphate, potassium, sulphur and oxygen is present.

Explanation: