1.
There are many examples of homogeneous and heterogeneous
mixtures in the world around you. How would you classify:
sea-water, air (unpolluted), smoke, black coffee, tea, soil,
soda water and wood ash?
2.
Characterize gases, liquids and solids in terms of compressibility,
fluidity and density.
3.
What is atomic theory proposed by Dalton? Describe how it
explains the great variety of different substances.
4.
Give normal state (solid, liquid or gas) of each of the
following:
(i) Nitrogen (ii) Copper (iii) Bromine (iv) Oxygen
(v) ethyl alcohol (vi) hydrogen peroxide
5.
Label each of the following as a substance, a heterogeneous
mixture, or a solution.
(i) bromine (iv) soil (in front of your home) (vii) river
water
(ii) petrol (v) stone (viii) Coal
(iii) concrete (vi) beach sand (ix) Soda water
6. Write the number of protons, neutrons
and electrons in each of the following:
199F, 188O, 4020Ca
7.
Give the symbol for each of the following isotopes
(i) Atomic number 19, mass number 40
(ii) Atomic number 18, mass number 40
(iii) Atomic number 7, mass number 15
8.
Boron has two isotopes with masses of 10.01294 and 11.00931
u and abundance of 19.77% and 80.23%. What is the average
atomic mass of boron?
9.
How does an element differ from a compound? How are elements
and compounds different than mixture?
10.
How will you define a solution based on its composition?
11.
Charge of one electron is 1.6022 × 10-19 coulomb.
What is the total charge on 1 mol of electron? If there
is same amount of charge on one proton, calculate total
charge on 1 mol of protons.
12.
How many molecules of O2 are in 8.00 g of O2?
If the O2 molecules were completely split into
O (oxygen atom), how many moles of atoms of oxygen would
be obtained?
13.
Assume that a human body is 80% water. Calculate the number
of the molecules of water that are present in the body of
a person who has mass of 65 kg.
14.
Using atomic masses given in the table of this lesson calculate
the molar masses of each of the following compounds:
COCH4, NaCl, NH3 and HCl
15.
Average atomic mass of carbon is 12.01 u. Find the number
of moles of carbon in (i) 2.00 g of carbon and (b) 3.00
× 1021 atoms of carbon.
