Chemistry for Railways

What you'll learn

A from-scratch, Class 10 level guide to the chemistry that RRB NTPC loves to ask: what matter is, what an atom is made of, how acids, bases and salts behave, and how metals, non-metals and common compounds differ — explained in simple English with a worked example and quick-revision tables.

This chapter has

Chemistry for Railways — solved practice questions

8 Railways General Science questions with step-by-step solutions. Attempt each, then reveal the answer.

1. Q1easy

   What is the chemical symbol for gold?

   • AGd
   • BAu
   • CAg
   • DGo
   Show answer & solution

   Correct answer: (B) Au

   The symbol for gold is Au, derived from its Latin name 'aurum'.

2. Q2easy

   The chemical formula of water is:

   • AH2O
   • BCO2
   • CO2
   • DH2O2
   Show answer & solution

   Correct answer: (A) H2O

   Water is H2O, made of two hydrogen atoms and one oxygen atom.

3. Q3easy

   Which gas is most abundant in the Earth's atmosphere?

   • AOxygen
   • BCarbon dioxide
   • CNitrogen
   • DArgon
   Show answer & solution

   Correct answer: (C) Nitrogen

   Nitrogen makes up about 78% of the atmosphere by volume, making it the most abundant gas.

4. Q4easy

   The pH value of a neutral solution at 25°C is:

   • A0
   • B14
   • C1
   • D7
   Show answer & solution

   Correct answer: (D) 7

   A neutral solution such as pure water has a pH of 7 at 25°C.

5. Q5medium

   Which of the following is an example of a noble gas?

   • AHydrogen
   • BHelium
   • CNitrogen
   • DChlorine
   Show answer & solution

   Correct answer: (B) Helium

   Helium is a noble (inert) gas belonging to Group 18 of the periodic table.

6. Q6easy

   Common salt used in food is chemically known as:

   • ASodium chloride
   • BSodium bicarbonate
   • CCalcium carbonate
   • DPotassium chloride
   Show answer & solution

   Correct answer: (A) Sodium chloride

   Common table salt is sodium chloride, with the formula NaCl.

7. Q7medium

   The gas released when an acid reacts with a metal like zinc is:

   • AOxygen
   • BCarbon dioxide
   • CHydrogen
   • DNitrogen
   Show answer & solution

   Correct answer: (C) Hydrogen

   Reaction of a dilute acid with an active metal such as zinc releases hydrogen gas.

8. Q8medium

   Which of the following is the lightest element?

   • AHelium
   • BOxygen
   • CCarbon
   • DHydrogen
   Show answer & solution

   Correct answer: (D) Hydrogen

   Hydrogen has atomic number 1 and is the lightest and simplest element.

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