Series JSK/1- Set 4

CBSE Board

Class X Science

Board Paper

Term 1 - 2021

Time: 90 minutes

Total Marks: 40

General Instructions:

1. This question paper contains 60 questions out of which 50 questions are to be attempted. All questions cony equal marks.
2. The question paper consists of three Sections — Section A, B and C.
3. Section A consists of 24 questions. Attempt any 20 questions from Q. No. 1 to 24.
4. Section B also contains 24 questions. Attempt any 20 questions from Q. No. 25 to 48.
5. Section C contains three Case Studies containing 12 questions and 4 questions in each case. Attempt any 10 from Q. No. 49 to 60.
6. There is only one correct option for every multiple choice question (MCQ). Marks will not be awarded for answering more than one option.
7. There is no negative marking.

SECTION-A

Section – A consists of 24 questions. Attempt any 20 questions from this section.

The first attempted 20 questions would be evaluated.

Question 1.

A student while burning a magnesium ribbon in air, collected the products in a wet watch glass. The new product obtained was:

1. Magnesium oxide
2. Magnesium carbonate
3. Magnesium hydroxide
4. Magnesium chloride

Question 2.

Consider the following chemical equation:

<math>2NaOH + H_2SO_4 \longrightarrow Na_2SO_4 + 2H_2O</math>

The information conveyed by this equation are:

NaOH reacts with H₂SO₄ to produce Na₂SO₄ and water.

For every one molecule of H₂SO₄, two molecules of NaOH are required.

Acids and bases are non-ionic in nature.

This is not a redox reaction.

The correct statements are:

1. I and II
2. II and III

1. III and IV
2. I and IV

Question 3.

Select the correct matching in the following table in connection with the given chemical reaction: <math>CuSO_4 + Fe \longrightarrow FeSO_4 + Cu</math>

1. В.

Initial colour of Final colour of Final colour of Type of

solution solution iron nail reaction

Pale green Blue Grey Displacement

Blue Pale green Brownish Double

displacement

Blue Light blue Grey Double

displacement

Blue Pale green Brownish Displacement C. D.

Question 4.

Consider the following processes:

1. Dilution of sulphuric acid
2. Sublimation of dry ice
3. Condensation of water vapours
4. Dissolution of ammonium chloride in water

The endothermic process(es) is/are:

1. I and III
2. II only
3. III only
4. II and IV

Question 5.

A solution gives yellowish orange colour when a few drops of universal indicator are added to it. This solution is of:

1. Lemon juice
2. Sodium chloride
3. Sodium hydroxide
4. Milk of magnesia

Question 6.

Concentrated H₂SO₄ is diluted by adding drop by drop:

1. Water to acid with constant stirring
2. Acid to water with constant stirring
3. Water to acid followed by a base
4. Base to acid followed by cold water