Unit 15: Environmental Chemistry II(Water)

What is Environmental Chemistry II (Water)?

Environmental Chemistry II focuses on the chemistry of water, examining the composition, quality, and chemical processes that influence water bodies on Earth. This unit introduces students to the essential role of water in ecosystems, the impact of pollutants, and the importance of water conservation. Key topics include the chemical reactions in natural and polluted waters, water treatment methods, and the environmental challenges related to water pollution.

Key Topics in Environmental Chemistry II (Water):

• Water Composition and Properties: Understanding the chemical structure of water, its physical properties, and its role as a universal solvent in chemical processes.
• Water Pollution: Exploring the sources and types of water pollutants, including industrial waste, agricultural runoff, and sewage, and their effects on aquatic ecosystems.
• Eutrophication: Studying the process of nutrient enrichment in water bodies, leading to algal blooms, oxygen depletion, and negative impacts on aquatic life.
• Water Treatment: Learning about the methods used to purify water, such as filtration, chlorination, and desalination, to ensure safe drinking water.
• Environmental Impact of Water Pollution: Examining the consequences of water pollution on human health, biodiversity, and the environment, along with strategies for prevention and remediation.

Benefits of Studying Environmental Chemistry II (Water):

• Understanding Water Quality: Provides essential knowledge about the factors that affect water quality and the importance of maintaining clean and safe water sources.
• Environmental Responsibility: Raises awareness about the impact of human activities on water resources and the need for sustainable water management practices.
• Critical Thinking: Enhances problem-solving skills by analyzing real-world water pollution issues and exploring effective solutions for water conservation.

This unit is vital for students to grasp the chemical principles that govern water quality and the significance of protecting water resources. Mastering Environmental Chemistry II is crucial for those interested in environmental science, public health, and sustainability.

1. Which one of the following properties of water is responsible for rising of water in plants?

a. specific heat capacity
b. surface tension
c. excellent solvent action
d. capillary action

2. Specific heat capacity of water is

a. 4.2 kJg^-1K^-1
b. 4.2 Jg^-1K^-1
c. 2.4 kJg^-1K^-1
d. 2.4 Jg^-1K^-1

3. Water dissolves non-ionic compound by

a. ion-ion forces
b. ion-dipole forces
c. dipole- dipole forces
d. hydrogen bonding

4. Temporary hardness is because of

a. Ca(HCO3)2
b. CaCO3
c. MgCO3
d. MgSO4

6. Permanent hardness is removed by adding

a. Na₂-zeolite
b. soda lime
c. lime water
d. quick lime

7. Which one of the following salts makes the water permanently hard ?

a. Na2CO3
b. NaHCO3
c. Ca(HCO3)2
d. CaSO4

8. Rapid growth of algae in water bodies is because of detergent having

a. carbonate salts
b. sulphonic acid salts
c. sulphate salts
d. phosphate salts

9. Depletion of O2 from water is not because of

a. decaying of aquatic plants
b. biodegradation of aquatic plants
c. rapid growth of aquatic plants
d. decomposition of aquatic plants

10. Which one of the following diseases causes liver inflammation?

a. typhoid
b. jaundice
c. cholera
d. hepatitis

11 Which one of the following diseases causes severe diarrhea and can be fatal

a. jaundice
b. dysentery
c. cholera
d. typhoid

12.Which one of the following gases is used to destroy harmful bacteria in water?

a. iodine
b. chlorine
c. fluorine
d. bromine

13. Which one of the following ions does not cause hardness in water?

a. Ca²⁺
b. Mg²⁺
c. SO₄^2-
d. Na⁺

14. A disease that causes bone and tooth damage is

a. fluorosis
b. hepatitis
c. cholera
d. jaundice

15. Ionic compounds are soluble in water due to

a. hydrogen bonding
b. ion-dipole forces
c. dipole -dipole forces
d. dipole-induced dipole forces

16. The chemicals used to kill or control pests are called pesticides. They are

a. dangerous inorganic chemicals
b. dangerous organic chemicals
c. beneficial inorganic chemicals
d. beneficial organic chemicals