Chemistry · Science General

Common Chemical Compounds and Reactions

1,204 Questions

Common chemical compounds and reactions questions test your knowledge of everyday chemicals, their formulas, and their interactions. Topics include properties of acids and bases, hard water chemistry, and compounds like baking soda and plaster of paris. This section is essential for general science preparation.

Acids and basesPlaster of parisHard water chemistryCommon chemical formulasEveryday chemical reactions

Common Chemical Compounds and Reactions Questions

Multiple choice

By what name is water which contains soluble salts of calcium and magnesium is known?

  1. soft water

  2. heavy water

  3. hard water

  4. mineral water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hard water contains dissolved calcium and magnesium ions (usually as sulfates, chlorides, or bicarbonates) that interfere with soap's cleaning action. Soft water has little or no dissolved calcium/magnesium. Heavy water contains deuterium oxide (D2O) and is used in nuclear reactors. Mineral water contains dissolved minerals but may or may not be 'hard'.

Multiple choice

The chemical composition of marble is mostly

  1. calcium carbonate

  2. potassium carbonate

  3. sodium carbonate

  4. strontium carbonate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Marble is a metamorphic rock formed from limestone, composed primarily of calcium carbonate (CaCO3). This gives marble its characteristic properties and reaction with acids.

Multiple choice

By the interaction of chlorine with which of the following is bleaching powder obtained?

  1. Dilute solution of calcium hydroxide

  2. Dry slaked lime

  3. Concentrated solution of calcium hydroxide

  4. Dry calcium oxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bleaching powder (calcium hypochlorite) is obtained by the interaction of chlorine with a dilute solution of calcium hydroxide (slaked lime). The reaction produces Ca(OCl)Cl which acts as the bleaching agent.

Multiple choice

Washing soda is not used

  1. in soap and glass industry

  2. in baking industry

  3. for removing permanent hardness of water

  4. as a cleaning agent
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Option (2) is the correct answer.

Multiple choice

What is the chemical name of baking soda?

  1. Sodium bicarbonate

  2. Sodium nitrate

  3. Sodium carbonate

  4. Potassium nitrate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Baking soda is the common name for sodium bicarbonate (NaHCO3), a white crystalline compound. It is used in baking as a leavening agent because it reacts with acids (like cream of tartar or buttermilk) to produce carbon dioxide gas, which makes baked goods rise. Sodium carbonate (washing soda) is a different compound. Sodium nitrate and potassium nitrate are used in fertilizers and food preservation.

Multiple choice

Which one of the following chemicals is a food preservative?

  1. Sodium carbonate

  2. Sodium bicarbonate

  3. Sodium benzoate

  4. Sodium thiosulphate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sodium benzoate is a widely used food preservative that inhibits the growth of bacteria, yeasts, and molds in acidic foods and beverages. It is particularly effective in soft drinks, pickles, and sauces. Sodium carbonate and bicarbonate are not preservatives; sodium thiosulphate is used in photography and medicine.

Multiple choice

Safety matches are made by using

  1. carbon, sulphur and paraffin

  2. potassium chloride, antimony sulphide and glue

  3. lead dioxide, carbon and paraffin

  4. silicon dioxide, sulphur and paraffin
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Safety match heads contain potassium chlorate (an oxidizer), antimony sulfide (fuel), and binding agents. The striking surface contains red phosphorus, which allows the match to ignite only when rubbed against it, preventing accidental ignition from friction alone.

Multiple choice

Which chemical compound is used for the etching of glass?

  1. Sodium bicarbonate

  2. Carbon monoxide

  3. Hydrofluoric acid

  4. Nitric acid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Hydrofluoric acid is unique in its ability to dissolve silica (SiO2), which is the main component of glass. This chemical reaction makes HF extremely hazardous to work with but indispensable for glass etching and frosting applications.

Multiple choice

Washing soda has formula

  1. Na₂CO₃.7H₂O

  2. Na₂CO₃.10H₂O

  3. Na₂CO₃.3H₂O

  4. Na₂CO₃
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Washing soda is Na₂CO₃.10H₂O.

Multiple choice

Which of the following sets is an example of double salt?

  1. Fischer salt, zeise’s salt, gmelin’s salt

  2. Magnus’ green salt, turnbull’s blue, mohr salt

  3. Glauber’s salt, microcosmic salt, carnallite

  4. Potash alum, mohr salt, gmelin’s salt

  5. Tutton salts, bromlite, peyrone's salt
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This option is correct because all are double salt.

Multiple choice

Oleum is prepared from

  1. sulphuric acid

  2. sulphur dioxide

  3. sulphur trioxide

  4. sulphur and water
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ans : 3.

Multiple choice

Give the scientific name of the marble used in buildings.

  1. Hydrated Calcium Sulphate

  2. Calcium Hydroxide

  3. Calcium Carbonate

  4. Sodium Bicarbonate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Marble used in buildings is primarily composed of Calcium Carbonate (CaCO3). Marble is a metamorphic rock formed from limestone under heat and pressure. While the question asks for the 'scientific name,' it's actually seeking the chemical composition of marble, which is indeed calcium carbonate.