Free Environmental Chemistry MCQs with Answers

151. Which is not a source of pollution?

• A. Forest fire
• B. Coal fire
• C. Volcanoes
• D. Dust storm

Explanation: Forest fire, coal fire and volcanoes are create smoke which is filled with CO, CO2 , NO2 etc like harmful gases therefore they are the sources of pollution.

152. U.V. radiation reacts in the atmosphere and produces:

• A. CFC
• B. Carbon dioxide
• C. Sulphur dioxide
• D. Ozone

Explanation: Oxygen molecule absorbs energetic UV radiations and dissociates into O atom. O atom reacts with O2 and forms ozone.

153. The disease that occurs due to eating high Hg content fish is:

• A. Minimata disease
• B. Beri-beri disorder
• C. Kwashiorkar disese
• D. Osteosclerosis

Explanation: Minamata disease is a neurological syndrome caused by severe mercury poisoning. Fishes that present in Hg contaminated water bodies efficiently store Hg in the form of highly toxic organic compound methylmercury in their bodies. Minimata disease is caused by eating these fishes.

154. Pollutant _ forms by burning of fossil fuels.

• A. Nitrogen dioxide
• B. Nitric acid
• C. Nitrous oxide
• D. Sulphur dioxide

Explanation: Industrial activities that burn sulfur containing fossil fuels form invisible gas sulfur dioxide.

155. The cause of the Stratosphere's ozone layer depletion is:

• A. CF2Cl2
• B. C6F16
• C. C6H6F6
• D. C6Cl6

Explanation: The main cause of the Stratosphere's ozone layer depletion is excessive release of man-made compound chlorofluorocarbons (CF2Cl2).

156. Which compound is not included under pollutants?

• A. NO2
• B. CO2
• C. O3
• D. CxHy

Explanation: 0.03% CO2 is present in our atmosphere and up to this range it is not considered a pollutant.

157. Which is the resulting disease due to depletion of ozone layer:

• A. Thyroid cancer
• B. Pulmonary cancer
• C. Skin cancer
• D. Breast cancer

Explanation: The ozone layer present in the stratosphere absorbs harmful ultraviolet light. Due to the depletion of the entersozone layer harmful ultraviolet light enter our earth and cause skin cancer.

158. _ is the uppermost region of the earth atmosphere.

• A. Stratosphere
• B. Troposphere
• C. Exosphere
• D. Ionosphere

Explanation: Earth's atmosphere on the basis of temperature is divided into the following layers. • Troposphere • Stratosphere• Mesosphere • Thermosphere• Exosphere - this region begins from 500 km above the surface of the earth. So it is the uppermost region of the earth's atmosphere.

159. Identify which one of the following water pollutant is Carcinogenic?

• A. Polycyclic hydrocarbons
• B. Mineral acids
• C. D.D.T
• D. Nitrate fertilizers

Explanation: Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds that are formed during incomplete combustion of organic matter, such as fossil fuels, wood, and tobacco. Many PAHs are known or suspected carcinogens, meaning they have the potential to cause cancer in humans. Explanation will be added soon.

160. Requirement of macronutrient per acre of the land is

• A. 5 - 200 kg
• B. 20-200 kg
• C. 200 - 400 kg
• D. 30 - 400 kg

Explanation: is indeed correct, although the lower end of the range seems exceptionally low for most agricultural scenarios and would likely be an outlier rather than the norm. Let's reconsider why option (a) might be correct:5 kg: While 5 kg per acre seems very low, it's not entirely implausible, especially for crops with very low nutrient requirements or in situations where soil fertility is exceptionally high.200 kg: On the other hand, 200 kg per acre represents a more typical upper limit of macronutrient requirements, especially for high-yield crops or intensive farming practices.Now we'll look at why other options are incorrect.The correct answer is (d) carbon.Explanation:(b) 20 - 200 kg:The lower limit of 20 kg per acre is more in line with typical agricultural practices compared to option (a)'s 5 kg. However, it might still be too low for many crops and situations, especially those aiming for higher yields or grown in soils with lower inherent fertility. Therefore, while the upper limit of 200 kg is reasonable, the lower limit might not adequately represent the lowest end of the macronutrient requirement spectrum.(c) 200 - 400 kg:While the upper limit of 400 kg per acre might be justified in certain intensive farming systems or in cases of severe soil nutrient depletion, it's generally considered excessive for typical agricultural scenarios. This range implies very high macronutrient requirements, which would be unsustainable in terms of cost, environmental impact, and potential nutrient runoff. Therefore, option (c) is incorrect as it overestimates the typical macronutrient requirements per acre.(d) 30 - 400 kg:Similar to option (c), the upper limit of 400 kg per acre is likely too high for most agricultural situations and could lead to issues like nutrient runoff, environmental degradation, and economic inefficiency. While the lower limit of 30 kg per acre is more reasonable compared to option (a)'s 5 kg, it still might not adequately represent the lowest end of the macronutrient requirement spectrum.(Environmental chemistry,Components of Environment)