Chemistry

Chemical Reactions and Processes

571 Questions

Chemical reactions and processes questions cover the transformation of substances through electrolysis, thermal decomposition, and catalysis. Key areas include identifying gas evolution, balancing chemical equations, and understanding industrial chemical applications. This general chemistry topic is a staple in the science sections of multiple competitive examinations.

Thermal decompositionElectrolysis processGas evolution reactionsHeterogeneous catalystsFuel cell components

Chemical Reactions and Processes Questions

Multiple choice

Which of the following is catalytic promoter?

  1. Arsenic

  2. CO

  3. Molybdenum

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is option is correct because it is a catalytic promoter. It acts as a promoter for iron catalyst in the manufacture of ammonia by Haber's process.

Multiple choice

What is shape selective catalysis?

  1. Catalysis by zeolite

  2. Catalysis by CO

  3. Catalysis by molybdenum

  4. Catalysis by arsenic
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct as shape selective catalysis is catalysis by zeolite. The reaction taking place in zeolite depends on the size and shape of the reactant and product molecules as compared to those pores and cavities of zeolite, that is why it is called as shape selective catalysis.

Multiple choice

In which of the following processes, Vanadium Pentoxide is used as a catalyst?

  1. Contact process

  2. Haber process

  3. Solvary process

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vanadium Pentoxide (V2O5) is used as a catalyst in the Contact process (option A). The Contact process produces sulfuric acid by oxidizing sulfur dioxide to sulfur trioxide, with V2O5 as the catalyst. The Haber process produces ammonia using iron catalysts, and the Solvay process produces sodium carbonate without V2O5.

Multiple choice

Which one of the following operations does not bring about a chemical change?

  1. Pressing dried up nitrogen tri-iodide.

  2. Mixing solid sodium bicarbonate with solid tartaric acid.

  3. Bringing phosphorus and oxygen in physical contact with each other.

  4. Passing electric current through acidified water.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pressing nitrogen tri-iodide triggers its explosive decomposition (chemical change). Mixing solid NaHCO3 with solid tartaric acid causes no reaction without water, so this is the only physical change. Phosphorus spontaneously ignites in oxygen (combustion, chemical change). Electrolysis of acidified water decomposes it into H2 and O2 gases (chemical change).

Multiple choice

What happens when copper chloride is electrolysed?

  1. Copper chloride is broken down to form copper.

  2. Chlorine gas is formed.

  3. It turns black in colour.

  4. Both 1 and 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If electricity is passed through a copper chloride solution, copper chloride is broken down to form copper metal and chlorine gas. Positively charged ions move to the negative electrode during electrolysis.

Multiple choice

When vanaspati oil reacts with hydrogen, it gets converted into vanaspati ghee. In this process, the catalyst used is

  1. Fe

  2. Mo

  3. V

  4. Ni
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Nickel (Ni) is used as a catalyst in the hydrogenation of vanaspati oil to convert it into vanaspati ghee. This process adds hydrogen to the double bonds in unsaturated fatty acids, making them more saturated and solid at room temperature. Nickel provides an effective catalytic surface for hydrogen addition under moderate temperature and pressure conditions.

Multiple choice

Solvay process cannot be extnded to manufacture of K2CO3 because of

  1. high heat of formation of K2CO3

  2. high solubility of K2CO3 in solution

  3. low hydration enthalpy of K+ ion

  4. low ionisation enthalpy of K2CO3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because of the high solubility of K2CO3 in solution it cannot be precipitated out as Na2CO3 and hence solvay process cannot be employed for the formation of K2CO3

Multiple choice

Mercury tree is formed by

  1. pouring mercury into silver nitrate solution

  2. heating of Hg with current chlorine

  3. reaction of ammonia with HgCl2

  4. reaction of HgCl2 with excess of potassium iodide

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This option is correct because when a little amount of mercury is poured into silver nitrate solution, a tree-like growth of silver amalgam is produced called mercury tree.