CBSE Class X – Science Chemistry Exam (Full Syllabus)

This test is designed based on NCERT Syllabus for Class 10 Topics of Science – Chemistry

Each time random 25 questions will be displaced from the question bank of 500 + Questions
So we recommend you to retake the quiz till you have mastered all the questions

1 / 25

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, the colour of the solution fades and a black precipitate is obtained.Why does the colour of the solution fades?

due to its reaction with hydrogen sulphide gas and results into the formation of colourless solution of sulphuric acid.

due to its reaction with Copper sulphate gas and results into the formation of colourless solution of sulphuric acid.

Both 1 & 2

all of these

2 / 25

Mention whether it is physical or chemical changes:- Burning of Liquefied Petroleum Gas (LPG)

chemical

physical

Both 1 & 2

none of these

3 / 25

Mention whether it is physical or chemical changes : Heating of an iron rod to red hot

physical

chemical

Both 1 & 2

none of these

4 / 25

State the reactions exothermic or endothermic in nature: Dilution of sulphuric acid

endothermic reaction

exothermic reaction

Both 1 & 2

none of these

5 / 25

When copper turning are added to silver nitrate solution, a blue coloured solution is formed after some time. It is because copper ?

Displaces silver from the solution

Forms a blue colored complex with AgNO₃

Is oxidized to Cu₂₊

Is reduced to Cu₂₊

6 / 25

Which of the following gives the exact increasing order of acid strength?

Water < acetic acid < hydrochloric acid

Water < hydrochloric acid < acetic acid

Acetic acid < water < hydrochloric acid

Hydrochloric acid < water < acetic acid

7 / 25

Which of the consequent will turn phenolphthalein pink?

NaOH(aq)

HCl(aq)

CH₃COOH(aq)

H₂O

8 / 25

Which of the following statements is accurate about an aqueous solution of an acid and a base?

Higher the pH, stronger the acid

Higher the pH, weaker the acid

Higher the pH, stronger the base

Lower the pH, weaker the base

1 and 3

2 and 3

2 and 4

1 and 4

9 / 25

What types of ions are formed when a base is dissolved in water ?

H+ ions are formed

OH- ions

allof these

10 / 25

Common name calcium sulphate hemihydrate

lime stone

Plaster of paris

white stone

none

11 / 25

Which of the subsequent elements will form an acidic oxide?

An element with atomic number 7

An element with atomic number 3

An element with atomic number 12

An element with atomic number 19

12 / 25

Arrange these elements in increasing order of their atomic radii

Carbon Nitrogen Oxygen Fluorine

Fluroine oxygen Nitrogen Oxygen

Nitrogen Oxygen Carbon Fluroine

Oxygen Nitrogen Fluroine Carbon

13 / 25

The valency of an element vary across a period

increases

Decreases

Remains constant

increases/decreases

14 / 25

The metallic character vary across the period

It moves right to left in peroidic table

It moves left to right in peroidic table

Remains constant

none of these

15 / 25

Is calcium?

metal

non metal

both

none of these

16 / 25

From which of the following substance pencil lead is formed?

Charcoal

Wood

Lead

Graphite

17 / 25

Unsaturated hydrocarbon undergoes incomplete combustion and burns with

blue fame

red fame

white fame

yellow fame

18 / 25

Ethene is

saturated hydrocarbon

unsaturated hydrocarbon

both 1 & 2

none

19 / 25

The molecular formula of Ethanol

C₂H₆OH

C₂H₇OH

C₂H₅OH

C₂HOOH

20 / 25

The next homologue of C₂H₄

C₃H₆

C₄H₅

C₃H₅

C₃H₇

21 / 25

An element A is mushy and can be cut with a knife. This is very reactive to air and cannot be kept in open air. It reacts vigorously with water. Identify the element from the following:

Mg

Na

P

Ca

22 / 25

The metals that float when dealt with water are:

Manganese and sodium

Manganesium and sodium

sodium and calcium

Magnesium and Calcium

23 / 25

2 ml each of conc. HCl, HNO₃, and a mixture of conc. HCl and conc. HNO3 in the ratio of 3:1 were taken in test tubes labelled as : A, B and C. A small piece of metal was put in each test tube. No change occurred in test tubes A and B but the metal got dissolved in test tube C. The metal could be:

AI

Au

Cu

Pt

2 and 4

1

2

1 and 3

24 / 25

Name two metals having melting point less than 310 K (37°C).

gold & silver

mercury & silver

cesium (Cs) and gallium (Ga).

none of these

25 / 25

Which metal is less reactive?

magnesium

calcium

both 1 & 2

none of these

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