Chemistry (Railway) Part-X

Total Questions: 23

21. Which of the following salts is an active ingredient in antacids? [RRB Group 'D' CBT Exam, 11.10.2022 (Shift-III)]

Correct Answer: (4) NaHCO₃
Solution:Sodium bicarbonate (NaH-CO₃) is an active ingredient in antacids.

• It is also Known as baking soda.

• It is used as an antacid to treat heartburn, indigestion, and upset stomach.

• It is a very quick-acting antacid.

22. aHNO₃(aq) + bCa(OH)₂(aq) → Ca(NO₃)₂ + CH₂O [RRB Group 'D' CBT Exam, 11.10.2022 (Shift-III)]

The coefficients a, b and c in the given balanced chemical equation are.

Correct Answer: (3) 2, 1 and 2, respectively
Solution:2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O is an example of both double displacement and neutralisation reactions.

• In this reaction, acid HNO₃ reacts with base Ca(OH)₂, and displacement of Hydrogen and calcium occurs.

23. Formation of slaked lime by the reaction of calcium oxide with water is an example of_____________. [RRB Group 'D' CBT Exam, 11.10.2022 (Shift-III)]

Correct Answer: (2) combination reaction
Solution:A combination reaction is a reaction where two or more elements or compounds combine to form a single compound. Calcium oxide combines with water to form slaked lime (calcium hydroxide).

• CaO (s) + H₂O (I) → Ca(OH)₂ (aq)