NATIONAL OPEN UNIVERSITY OF NIGERIA
14/16 AHMADU BELLO WAY, VICTORIA ISLAND, LAGOS
SCHOOL OF SCIENCE AND TECHNOLOGY
MARCH/APRIL 2014 EXAMINATION
COURSE CODE: CHM 314
COURSE TITLE: ENVIRONMENTAL CHEMISTRY
TIME ALLOWED: 2 HOURS
INSTRUCTION: ANSWER ANY FOUR QUESTIONS
Question One
a) i. State the four major reservoirs involved in the carbon cycle (4mks).
ii. List the form(s) in which carbon exist in :
1. The atmosphere
2. Water
3. Rocks (4⅟2 mks)
b) i. State and explain any two ways by which carbondioxide (CO2) is released into the atmosphere. (8mks)
ii. List one form by which sulphur exist on the earth surface
(1 mk)
Question Two
a) With respect to their distance from the Earth’s surface and characteristics, distinguish between the troposphere and stratosphere. (9 mks)
b) i. Why is the upper layer of the stratosphere warmer. ( 3 marks)
ii.What is/are effect(s) of the use of chlorofluorocarbons, in the atmosphere. Write appropriate
chemical reaction(s) where necessary (5⅟2 marks)
Question Three
a) i. What are pollutants?. (2mks)
ii. State one effect experienced by a polluted water body.(2mks)
iii. State and explain the two broad types of chemical release into the environment.(6mks)
b) i. What is Eutrophication ?.(2mks
ii. State one source and one effect of the following in the aquatic environment :
1. Crude oil
2. Eutrophication (6 mks)
Question Four
(a) i. State two constituents of municipal wastewater (2mks)
ii. Why is it necessary to treat municipal wastewater before discharging it into the aquatic environment (5⅟2 mks)
(b) Differentiate between the following
1.Primary treatment and Secondary treatment of wastewater (6mks)
2. Screening and Sedimentation (6mks)
Question Five
a) i. Define the following
1.Solid waste (3mks)
2.Solid waste management (4mks)
ii.State the types of solid waste and explain briefly any two of the types of solid wastes (6mks)
b) Discuss briefly Recycling. (4⅟2 marks)
Question Six
a) i. Explain briefly the sources of the following physical parameters of water
1. Turbidity (4mks)
2. Colour (4mks)
b) i. Differentiate between Total dissolved solids and total suspended solids (4⅟2 marks)
ii.Explain how the total solids in a water sample can be determined (2mks)
iii. State any one significance of solids determination.(3mks).
For the 2015 – till date past questions for this course CLICK HERE
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