Explore topic-wise MCQs in Science.

This section includes 95 Mcqs, each offering curated multiple-choice questions to sharpen your Science knowledge and support exam preparation. Choose a topic below to get started.

51.

Calcium hydroxide (slaked lime) is used in:

A. plastics and dyes   
B. fertilizers
C. X is a metal and Y is basic oxide.
D. whitewashing
Answer» E.
52.

Which of the following is an organic acid?

A. Acetic acid  
B. Tartaric acid
C. Turmeric 
D. All the above
E. None of these
Answer» E. None of these
53.

Substances whose solutions do not change the colour of any indicator in any way are called:

A. Basic substances
B. Acidic substances
C. make the waste basic before disposal
D. Substances
E. None of these
Answer» D. Substances
54.

Which of the following match is incorrect? Indicator Acid Base (i) Methyl Orange  Red Yellow (ii) Phenolphthalein Pink Colourless (iii) Litmus Red Blue (iv) China rose Green Magenta

A. (i) and (ii)
B. (ii) and (iv) 
C. \[N{{a}_{2}}C{{O}_{3}}\]  
D. (iii) and (iv)
E. None of these
Answer» C. \[N{{a}_{2}}C{{O}_{3}}\]  
55.

Which of the following is formed by the reaction of an acid with a base?

A. A salt   
B. An indicator
C. Nitric acid   
D. All of the above  
Answer» B. An indicator
56.

Who devised pH scale?

A. Sorenson   
B. Bohr  
C. Sugar   
D. Arrhenius
Answer» D. Arrhenius
57.

Compound 'X' in the aqueous form reacts with ammonium carbonate to give an acidic gas. What is compound 'X'?

A. Calcium hydroxide
B. Ethanoic acid
C. Stain was of ice-cream and the cloth washing bar was acidic.
D. Sulphuric acid
Answer» E.
58.

Which of the following compounds dissolves in water to give a solution with a pH greater than 7?

A. Calcium carbonate
B. Copper (II) hydroxide
C. turn blue litmus red 
D. Sulphur dioxide
Answer» D. Sulphur dioxide
59.

Identify the acid used for producing explosives.

A. \[HN{{O}_{3}}\]
B. \[{{H}_{2}}S{{O}_{4}}\]
C. XYPQRAt cathodeAt anode\[C{{l}_{2}}\] gas\[{{H}_{2}}\] gas\[NaHC{{O}_{3}}\]   
D. \[{{H}_{3}}P{{O}_{4}}\]
Answer» B. \[{{H}_{2}}S{{O}_{4}}\]
60.

A solid element 'X' is a non-metal. It can form

A. an acidic oxide.
B. a basic oxide.
C. PQRS Sodium hydroxideSodium hydrogen carbonate Calcium hydroxide Milk of magnesia 
D. a metallic salt.
Answer» B. a basic oxide.
61.

Which of the following is a dibasic acid?

A. \[HCl\]  
B. \[{{H}_{3}}P{{O}_{4}}\]
C.  Abase
D. \[{{H}_{2}}S{{O}_{4}}\]
Answer» E.
62.

Statement I: Metal ions are Lewis acids. Statement II: Metal ions are electron pair acceptors. [NDA]   

A. Both the statements individually true and Statement II is the correct explanation of Statement I.
B. Both the statements are individually true but Statement II is not correct explanation of Statement I.
C. Statement I is true but Statement II is false.
D. Statement I is false but Statement II is true.
Answer» B. Both the statements are individually true but Statement II is not correct explanation of Statement I.
63.

Which among the following statements with regard to pH scale is/are correct? [NDA] I. It is a logarithmic scale. II. The scale is limited to 0-14 because the ionic product of water is about \[{{10}^{-14}}\] III. The lower the value of pH, the greater is the acidity of the solution. Select the correct answer using the code given below

A. I and II only
B. I, II and III
C. I and III only
D. II only
Answer» C. I and III only
64.

Which one among the following is not a property of salt? [NDA]

A. Salts have ordered packing arrangements called lattices
B. Salts have low melting points but high boiling points
C. Salts are brittle
D. Salts conduct electricity when dissolved in water or even in the molten state
Answer» C. Salts are brittle
65.

Food cans are coated with tin and not with zinc because [CDS]

A. zinc is costlier than tin.
B. zinc has a higher melting point than tin.
C. zinc is more reactive than tin.
D. zinc is less reactive than tin.
Answer» D. zinc is less reactive than tin.
66.

What is anode mud?

A. Fan of anode
B. Metal of anode
C. Impurities collected at anode in electrolysis during purification of metals
D. All of these
Answer» D. All of these
67.

 Column-I(Product)  Column-II (Name of alloy) A. Aircrafts P. Stainless steel B. Utensils Q. Bronze C. Medals R. Magnalium D. Balance beam S. Duralumin 

A. A-S;B-P;C-Q;D-R
B. A-P;B-S;C-Q;D-R
C. A-S;B-P;C-R;D-Q
D. A-P;B-S;C-R;D-Q
Answer» B. A-P;B-S;C-Q;D-R
68.

Which method is employed for obtaining a pure metal?

A. Froth floatation
B. Electrolytic refining
C. Magnetic separation
D. Gravity separation
Answer» C. Magnetic separation
69.

Aluminium is used in thermite welding because -

A. aluminium is a light metal
B. aluminium has more affinity for oxygen
C. aluminium is a strong oxidising agent
D. aluminium is a reactive metal
Answer» C. aluminium is a strong oxidising agent
70.

Removal of impurities from ore is known as -

A. crushing and grinding
B. concentration of ore
C. calcination
D. roasting
Answer» C. calcination
71.

The acid in gastric juice is [NDA]

A. acetic acid
B. nitric acid
C. hydrochloric acid
D. sulphuric acid
Answer» D. sulphuric acid
72.

Which of the following is not correct about Baking Soda? [CDS]

A. It is used in soda acid fire extinguisher
B. It is added for faster cooking.
C. It is a corrosive base
D. It neutralizes excess acid in the stomach
Answer» D. It neutralizes excess acid in the stomach
73.

Antacids are commonly used to get rid of acidity in the stomach. A commonly used antacid is [CDS]

A. sodium hydrogen phthalate
B. magnesium hydroxide
C. calcium hydroxide
D. manganese acetate
Answer» C. calcium hydroxide
74.

Which one among the following is an electrochemical cell that cannot be charged? [NDA]

A. Electrolytic cell
B. Storage cell
C. Primary cell
D. Fuel cell
Answer» D. Fuel cell
75.

Which one among the following is the correct order of strength of acids? [NDA]

A. \[{{H}_{2}}S{{O}_{4}}>{{H}_{3}}P{{O}_{3}}>C{{H}_{3}}COOH\]
B. \[{{H}_{3}}P{{O}_{3}}>{{H}_{2}}S{{O}_{4}}>C{{H}_{3}}COOH\]
C. \[C{{H}_{3}}COOH>{{H}_{3}}P{{O}_{3}}>{{H}_{2}}S{{O}_{4}}\]
D. \[C{{H}_{3}}COOH>{{H}_{2}}S{{O}_{4}}>{{H}_{3}}P{{O}_{3}}\]
Answer» B. \[{{H}_{3}}P{{O}_{3}}>{{H}_{2}}S{{O}_{4}}>C{{H}_{3}}COOH\]
76.

The following equation is an example of a redox reaction, in which \[C{{l}_{2}}\] is the oxidizing agent and \[FeB{{r}_{3}}\] is the reducing agent: \[2FeB{{r}_{3}}\,\,(aq)\,\,+\,\,3C{{l}_{2}}\,\,(g)=2FeCl\,{{\,}_{3}}(aq)\,\,+\,\,3B{{r}_{2}}\,\,(1)\] Which one among the following statements is incorrect for this redox reaction? [NDA]

A. Oxidizing agents are themselves reduced
B. Reducing agents gain or appear to gain electrons
C. Reducing agents are themselves oxidized
D. Oxidizing agents oxidize other substances
Answer» C. Reducing agents are themselves oxidized
77.

Bleaching powder gives smell of chlorine because it-

A. is unstable
B. gives chlorine on exposure to atmosphere
C. is a mixture of chlorine and slaked lime
D. contains excess of chlorine
Answer» C. is a mixture of chlorine and slaked lime
78.

Washing soda has the formula -

A. \[N{{a}_{2}}C{{O}_{3}}.7{{H}_{2}}O\]
B. \[N{{a}_{2}}C{{O}_{3}}.10{{H}_{2}}O\]
C. \[N{{a}_{2}}C{{O}_{3}}.{{H}_{2}}O\]
D. \[N{{a}_{2}}C{{O}_{3}}\]
Answer» C. \[N{{a}_{2}}C{{O}_{3}}.{{H}_{2}}O\]
79.

Chemical formula of baking soda is -

A. \[MgS{{O}_{4}}\]
B. \[N{{a}_{2}}C{{O}_{3}}\]
C. \[NaHC{{O}_{3}}\]
D. \[MgC{{O}_{3}}\]
Answer» D. \[MgC{{O}_{3}}\]
80.

Plaster of parts is made from -

A. limestone
B. slaked lime
C. quicklime
D. gypsum
Answer» E.
81.

pH of human body varies within the range of

A. 6.0 to 6.5
B. 5.5 to 5.8
C. 7.0 to 7.8
D. 7.0 to 11.0
Answer» D. 7.0 to 11.0
82.

On which of the following acid rain has adverse effects?

A. Marble structures
B. Historical monuments
C. Aquatic life
D. All of these
Answer» E.
83.

When vinegar reacts with baking soda the gas evolved is

A. hydrogen
B. oxygen
C. carbon dioxide
D. nitrogen dioxide
Answer» D. nitrogen dioxide
84.

 Which of the following is known as dead burnt plaster?

A. Quicklime
B. Slaked lime
C. Limestone
D. Gypsum
Answer» C. Limestone
85.

Aqueous solution of which of the following salt will change the colour of red litmus to blue?

A. \[N{{a}_{2}}C{{O}_{3}}\]
B. \[N{{a}_{2}}C{{O}_{3}}.10{{H}_{2}}O\]
C. Both [a] and [b]
D. None of these
Answer» D. None of these
86.

If pH of A, B, C and D are 9.5, 2.5, 3.5 and 5.5 respectively, then strongest acid is

A. A
B. C
C. D
D. B
Answer» E.
87.

Which of the following compounds is basic in nature?

A. \[Ca{{(OH)}_{2}}\]
B. \[CaC{{l}_{2}}.6{{H}_{2}}O\]
C. \[NaCl\]
D. \[CuS{{o}_{4}}.5{{H}_{2}}O\]
Answer» B. \[CaC{{l}_{2}}.6{{H}_{2}}O\]
88.

Which of the following is a weak base?

A. NaOH
B. KOH
C. \[N{{H}_{4}}OH\]
D. none of these
Answer» D. none of these
89.

Acids and bases are important because of

A. their use in industry
B. their effects on human health
C. their effect on farmer's crop
D. all the above are correct.
Answer» E.
90.

Which of the following is considered a mineral acid?

A. Oxalic acid
B. Lactic acid
C. Citric acid
D. Phosphoric acid
Answer» E.
91.

 Plaster of parts is obtained -

A. by adding water to calcium sulphate
B. by adding sulphuric acid to calcium hydroxide
C. by heating gypsum to a very high temperature
D. by heating gypsum to 373 K.
Answer» E.
92.

Plaster of parts has the formula -

A. \[CaS{{O}_{4}}.1/2{{H}_{2}}O\]
B. \[CaS{{O}_{4}}.{{H}_{2}}O\]
C. \[CaS{{O}_{4}}.1{\scriptstyle{}^{1}/{}_{2}}{{H}_{2}}O\]
D. \[CaS{{O}_{4}}.2{{H}_{2}}O\]
Answer» B. \[CaS{{O}_{4}}.{{H}_{2}}O\]
93.

Which of the following acid is present in sour milk?

A. glycolic acid
B. lactic acid
C. citrus acid
D. tartaric acid
Answer» C. citrus acid
94.

Which of the following is acidic in nature -

A. apple juice
B. soap solution
C. slaked lime
D. lime
Answer» B. soap solution
95.

A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains

A. NaCl
B. HCl
C. LiCI
D. KCl
Answer» C. LiCI