All Free Chemistry MCQs with Answers

• A. The reaction proceeds in the forward direction at 300 K
• B. At 1200 K, reaction proceeds in the reverse direction
• C. At 300 K, Kp > 1
• D. At 300 K, the products will be favoured more than reactants at equilibrium

Explanation: This is the following solution: kp is less than one, reaction is non spontaneous for sponataneous reactions kp is greater than one

• 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…

• A. alum
• B. BOD
• C. COD
• D. All of the above

Explanation: Alum, or aluminum sulfate, is commonly used as a coagulant in the purification of portable water.

• A. Ammonia
• B. Dissolved Oxygen
• C. Carbon Dioxide
• D. All

Explanation: Option (d) is correct because chlorination of water containing any of these substances can be harmful due to the formation of disinfection…

• A. 60
• B. 70
• C. 80
• D. 90

Explanation: In many coagulation processes, achieving an 80% removal of suspended solids from raw water is indeed feasible.

• A. The human body does not produce enzymes
• B. The human body does not produce vitamins
• C. Proteins are an energy source for our body
• D. Nucleic acids are building blocks for our body

Explanation: With few exceptions, vitamins are essential nutrients that the human body cannot synthesize and must therefore be obtained through diet.

• A. Eyes
• B. Ears
• C. Stomach
• D. Nose

Explanation: PANs have many adverse effects in the human body such as reduced respiratory function (including emphysema and impaired breathing) and eye…

• A. 100
• B. 10,000
• C. 10,00,000
• D. 100,000

Explanation: A single chloride free radical can destroy upto 100,000 ozone molecules.

• A. NO
• B. NO2
• C. SO2
• D. CO2

Explanation: The yellow colour in photochemical smog is due to the presence of nitrogen dioxide.

• A. NaOH
• B. NaHCO3
• C. Na2CO3
• D. CuSO4
• E. NaCl

Explanation: Halite more commonly known as Rock salt is a mineral formed from sodium chloride.

• A. Phosphorus Cycle
• B. Nitrogen Cycle
• C. Carbon Cycle
• D. All of these

Explanation: In nitrogen cycle :Nitrogen-fixing bacteria convert N2 to ammoniaNitrifying bacteria convert ammonia to nitrates and nitritesDenitrifying…

• A. Organic pollutant in water
• B. Oxides of SPN in air
• C. Inorganic pollutant in water
• D. Particle matter in water

Explanation: BOD is the amount of oxygen needed to decompose the organic material present in the water.

• A. In the morning of winters
• B. Around mid day in summer months
• C. In rainy day
• D. When concentration of particulate matter is very low

Explanation: To form Photochemical smog, the presence of sunlight (high temperature) requires when nitrogen oxide reacts with volatile organic compounds.

• A. CO
• B. CH4
• C. Chlorofluorocarbons
• D. SO2

Explanation: Greenhouse gases are carbondioxide, nitrous oxide, methane, carbon monoxide, water vapours and CFCs (chlorofluorocarbons).

• A. O3
• B. CO
• C. CO2
• D. CHO

Explanation: During the formation of photochemical smog, NO2 breaks into NO, and O. O reacts with O2 producing O3, hence O3 is always present in…

• A. Weathering of phosphate rocks only
• B. Agricultural fertilizers
• C. Phosphate rocks and sewage
• D. Sewage and agricultural fertilizers

Explanation: Phosphate pollution occurs by Sewage and agricultural fertilizers. Algal blooms occurs when phosphate in large amount enters in water…

• A. n-pentane
• B. Iso-pentane
• C. Neo-pentane
• D. All same

Explanation: The intermolecular forces in n-pentane are STRONGER than those in isopentane and neopentane.

• A. Increase
• B. Decrease
• C. Constant
• D. Unknown

Explanation: When a liquid is heated, the kinetic energy of its molecules increases and hence the temperature also increases.

• A. FILTER HOT SOLUTION
• B. Avoid premature crystallization
• C. )INCREASE Rate of crystallization
• D. decrease the size

Explanation: The correct option here is (A) FILTER HOT SOLUTIONS.Fluted filter paper is primarily used to filter hot solutions or substances.

• A. solution
• B. amount of insoluble solute
• C. amount of soluble solute
• D. Amount of solvents

Explanation: The size of filter paper is generally selected based on the amount of (a) solution being filtered.Here's why the other options are…