Calculate the molar mass of the following substances.
(a) Ethyne, C2H2
(b) Sulphur molecule, S8
(c) Phosphorus molecule, P4 (Atomic mass of phosphorus = 31)
(d) Hydrochloric acid, HCl
(e) Nitric acid, HNO3
Give the names of the elements present in the following
compounds.
(a) Quick lime
(b) Hydrogen bromide
(c) Baking powder
(d) Potassium sulphate.
Write the chemical formulae of the following.
(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate
(d) Aluminium chloride
(e) Calcium carbonate.
When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of
carbon dioxide is produced. What mass of carbon dioxide will
be formed when 3.00 g of carbon is burnt in 50.00 g of
oxygen? Which law of chemical combination will govern your
answer?
A 0.24 g sample of compound of oxygen and boron was found
by analysis to contain 0.096 g of boron and 0.144 g of oxygen.
Calculate the percentage composition of the compound by
weight.
Calculate the formula unit
masses of ZnO, Na2O, K2CO3,
given atomic masses of Zn = 65 u,
Na = 23 u, K = 39 u, C = 12 u,
and O = 16 u.
How many atoms are present in a
(i) H2S molecule and
(ii) PO43– ion?
compounds represented by the_________
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