Chemistry Q 01
1. A Compound Consists of 80% by mass of carbon and 20 by mass of hydrogen. Calculate its empirical formula.
Ans: Empirical Formula C1:H3 CH3
C:H
80/12:20/1
moles = 6.667/6.667:20/6.667
divide by he smallest
=> 1:3
2.Which separating techniques can be used to
separate a solution(mixture of a solute and solvent).
Ans: Simple Distillation
3 Study the electronic configuration of
sodium and chorine atoms
-sodium: 2.8.1
-chorine: 2.8.7
what is the charges of sodium atom?
Ans :Positive Charge
4.which non metal is used to sterilize water?
Ans: Chlorine
5.Define the term isotopes?
Ans: I isotopes are atoms of the same element
having the same number of of protons
but different number of neutrons.
6. An Acid is said to have a sour taste.
What particle of an ACID is responsible
for the sour taste?
Ans: Hydrogen ion: Acidity is determined by
the number of Hydrogen ion
7.Define a salt and give one example.
Ans: A salt is a compound formed when
when the hydrogen ions in an acid are replaced
by metal ions or by ammonium ions e.g. Barium
sulphate.
8.Name a salt that can be prepared
by precipitation
Ans: calcium sulphate: insoluble salt can be
prepared by precipitations.
9. work out the relative formula
of the following
i) Ca(HCO3)2
Ans:40 + (2x1)+(2x12)+(6x16) = 162
ii) Al2(so4)3
Ans:(2x27)+(3x32)+(12x16) = 342
10. why are some metals used
to make bells?
Ans: Metals Have the properties of malleable
and ductile(means flexible but strong and tough).
so these properties helps them to vibrate and ring.