Chemistry · NDA previous year questions

Which one of the following statements is correct?

1. A.Only electrons reside inside the nucleus of an atom
2. B.Both electrons and protons reside inside the nucleus of an atom
3. C.Only neutrons reside inside the nucleus of an atom
4. D.Both protons and neutrons can reside inside the nucleus of an atom

The metal atom, which is present in superphosphate, is

1. A.sodium (Na)
2. B.potassium (K)
3. C.calcium (Ca)
4. D.magnesium (Mg)

Which one among the following metals is more reactive than hydrogen?

1. A.Mercury
2. B.Copper
3. C.Silver
4. D.Tin

Which one of the following is a transition metal?

1. A.Aluminium (Al)
2. B.Manganese (Mn)
3. C.Magnesium (Mg)
4. D.Calcium (Ca)

Which one of the following gases, present in the air near the surface of the Earth, has maximum concentration?

1. A.Oxygen (${\mathrm{O}}_2$)
2. B.Hydrogen (${\mathrm{H}}_2$)
3. C.Nitrogen (${\mathrm{N}}_2$)
4. D.Methane ($\mathrm{C}{\mathrm{H}}_4$)

Which one of the following elements will replace hydrogen from acids to form salts?

1. A.Sulphur (S)
2. B.Silicon (Si)
3. C.Zinc (Zn)
4. D.Phosphorus (P)

Which of the following represent a chemical change? 1. Magnetization of iron 2. Condensation of liquid 3. Burning of fuel 4. Rusting of iron Select the correct answer using the code given below: Code:

1. A.1 and 2
2. B.2 and 3
3. C.3 and 4
4. D.1 and 4

Which one among the following is the correct order of reactivity of the elements?

1. A.$\mathrm{Cu}>\mathrm{Mg}>\mathrm{Zn}>\mathrm{Na}$
2. B.$\mathrm{Na}>\mathrm{Zn}>\mathrm{Mg}>\mathrm{Cu}$
3. C.$\mathrm{Cu}>\mathrm{Zn}>\mathrm{Mg}>\mathrm{Na}$
4. D.$\mathrm{Na}>\mathrm{Mg}>\mathrm{Zn}>\mathrm{Cu}$

Vinegar is produced from

1. A.ethanoic acid
2. B.valeric acid
3. C.methanoic acid
4. D.butanoic acid

Match List-I with List-II and select the correct answer using the code given below the Lists: | List-I | List-II | | :--- | :--- | | A. Ozone gas | 1. Combines with haemoglobin | | B. Nitrous oxide | 2. Ultraviolet radiation | | C. Carbon dioxide | 3. Component of air in small quantity | | D. Carbon monoxide | 4. Visible radiation | | | 5. Infrared radiation | Code:

1. A.A-1, B-4, C-5, D-3
2. B.A-2, B-3, C-5, D-1
3. C.A-1, B-4, C-3, D-2
4. D.A-2, B-5, C-3, D-1

The major combustible component of gobar (cow-dung) gas is

1. A.methane
2. B.carbon dioxide
3. C.hydrogen
4. D.propane

Release of which one of the following chemicals is responsible for causing fatigue after muscular activity in human beings?

1. A.Glucuronic acid
2. B.Uric acid
3. C.Pyruvic acid
4. D.Lactic acid

A book is kept on the surface of a table. If the gravitational pull of the earth on the book is the force of action, then the force of reaction is exerted by

1. A.the book on the table
2. B.the book on the earth
3. C.the table on the book
4. D.the table on the earth

Which one of the following elements exists in liquid state at room temperature?

1. A.Mercury
2. B.Lead
3. C.Sodium
4. D.Calcium

Aluminium is more reactive than iron but aluminium is less easily corroded than iron, because

1. A.oxygen forms a protective oxide layer
2. B.it is a noble metal
3. C.iron undergoes reaction easily with water
4. D.iron forms ions

According to which one of the following laws it is indicated that when two or more gases react with one another, their volumes bear a simple ratio?

1. A.Law of mass action
2. B.Law of multiple proportions
3. C.Law of reciprocal proportions
4. D.Law of combining volumes

Acid turns blue litmus red and base turns red litmus blue. A student tested a liquid with a red litmus paper which remained red with no change. This shows that the liquid

1. A.is not a base
2. B.is not an acid
3. C.is neither an acid nor a base
4. D.must be pure water

Arrange the following bases in increasing order of their basic strength : 1. Sodium hydroxide 2. Magnesium hydroxide 3. Aluminium hydroxide 4. Ammonium hydroxide Select the correct answer using the code given below : Code :

1. A.4-2-1-3
2. B.4-1-2-3
3. C.4-3-2-1
4. D.1-2-3-4

Consider the following statements : 1. Soap cannot be used in acidic water. 2. Ionic part of a soap is $-\mathrm{CO}{\mathrm{O}}^{-}.\mathrm{N}{\mathrm{a}}^{+}$. 3. Soap dissolves in water faster than detergent. Which of the statements given above is/are correct?

1. A.1 and 2
2. B.2 and 3
3. C.3 only
4. D.1 only

Match List-I with List-II and select the correct answer using the code given below the Lists : $$\begin{array}{ll}\text{List-I}\text{(Material)}& \text{List-II}\text{(Important Ingredient)}\\ \text{A. Cement}& \text{1. Sodium salt of fatty acids}\\ \text{B. Glass}& \text{2. Carbon black}\\ \text{C. Ink}& \text{3. Silica in the form of quartz}\\ \text{D. Soap}& \text{4. Aluminates and silicates of calcium}\end{array}$$ $\text{Code :}$

1. A.A-4, B-3, C-2, D-1
2. B.A-1, B-2, C-3, D-4
3. C.A-1, B-3, C-2, D-4
4. D.A-4, B-2, C-3, D-1

The concentration of hydrochloric acid in a given solution is $10^{-8}M$. What is the value of pH for this solution?

1. A.7
2. B.$>7$ but not 14
3. C.$<7$
4. D.14

Following statements are made in connection with carbon dioxide ($\mathrm{C}{\mathrm{O}}_2$) : 1. $\mathrm{C}{\mathrm{O}}_2$ is a poisonous gas. 2. $\mathrm{C}{\mathrm{O}}_2$ is an acidic oxide. 3. $\mathrm{C}{\mathrm{O}}_2$ turns limewater milky. Which of the statements given above is/are correct?

1. A.1 and 2
2. B.2 and 3
3. C.3 only
4. D.1 and 3

Which of the following is the best example of the law of conservation of mass?

1. A.When 12 gm of carbon is heated in vacuum, there is no change in mass
2. B.Weight of platinum wire is the same before and after heating
3. C.A sample of air increases in volume when heated at constant pressure but mass remains unchanged
4. D.12 gm of carbon combines with 32 gm of oxygen to give 44 gm of carbon dioxide

Directions : The following three (3) items consist of two statements, one labelled as 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the code given below : Code : (a) Both A and R are individually true and R is the correct explanation of A (b) Both A and R are individually true but R is not the correct explanation of A (c) A is true but R is false (d) A is false but R is true Assertion (A) : On a wet floor of a bathroom, a small circular area around a pinch of foam appears to be dry. Reason (R) : Soap molecules reduce surface tension and increase surface area of the thin layer of water on the wet floor.

1. A.A
2. B.B
3. C.C
4. D.D

The metal compound commonly found in Sindhoor or Kumkum is based on

1. A.Tin
2. B.Lead
3. C.Copper
4. D.Zinc