Question 1

Question 1A student took Sodium Sulphate solution in a test tube and added Barium Chloride solution to it. He observed that an insoluble substance has formed. The colour and molecular formula of the insoluble substance is:Grey, Ba2SO4Yellow, Ba(SO4)2White, BaSO4Pink, BaSO4

Accepted Answer

White, BaSO4Reason — When sodium sulphate is reacted with barium chloride, a white ppt. of barium sulphate is produced.Na2SO4 (aq) + BaCl2 (aq) ⟶ BaSO4 (s) + 2NaCl (aq)

Question 2

Question 2Which of the following oxide(s) is/are soluble in water to form alkalis?(i) Na2O(ii) SO2(iii) K2O(iv) NO2(i) and (iii)(i) only(ii) and (iv)(iii) only

Accepted Answer

(i) and (iii)Reason — Sodium oxide and potassium oxide dissolve in water to form alkalis.Na2O + H2O ⟶ 2NaOHK2O + H2O ⟶ 2KOH

Question 3

Question 3Study the diagram given below and identify the gas formed in the reaction.Carbon di-oxide which extinguishes the burning candle.Oxygen due to which the candle burns more brightly.Sulphur dioxide which produces a suffocating smell.Hydrogen which while burning produces a popping sound.

Accepted Answer

Hydrogen which while burning produces a popping sound.Reason — When zinc reacts with sulphuric acid, it produces hydrogen gas and zinc sulphate.Zn + H2SO4 ⟶ ZnSO4 + H2↑

Question 4

Question 4Sodium reacts with water to form sodium hydroxide and hydrogen gas. The balanced equation which represents the above reaction isNa(s) + 2H2O(l) ⟶ 2NaOH(aq) + 2H2(g)2Na(s) + 2H2O(l) ⟶ 2NaOH(aq) + H2(g)2Na(s) + 2H2O(l) ⟶ NaOH(aq) + 2H2(g)2Na(s) + H2O(l) ⟶ 2NaOH(aq) + 2H2(g)

Accepted Answer

2Na(s) + 2H2O(l) ⟶ 2NaOH(aq) + H2(g)Reason — The balanced equation for the reaction between sodium and water to form sodium hydroxide and hydrogen gas is:2Na(s) + 2H2O(l) ⟶ 2NaOH(aq) + H2(g)

Question 5

Question 5Which of the options in the given table are correct?OptionNatural SourceAcid Present(i)OrangeOxalic acid(ii)Sour milkLactic acid(iii)Ant stingMethanoic acid(iv)TamarindAcetic acid(i) and (ii)(i) and (iv)(ii) and (iii)(iii) and (iv)

Accepted Answer

(ii) and (iii)Reason — Sour milk contains lactic acid and ant sting contains methanoic acid.

Question 6

Question 6C6H12O6 (aq) + 6O2 (aq) ⟶ 6CO2 (aq) + 6H2O (l)The above reaction is a/andisplacement reactionendothermic reactionexothermic reactionneutralisation reaction

Accepted Answer

exothermic reactionReason — The name of the above reaction is respiration and it is an exothermic reaction. The glucose from food combines with oxygen in the cells of our body and provides energy as heat.

Question 7

Question 7Which of the following statements about the reaction given below are correct?MnO2 + 4HCl ⟶ MnCl2 + 2H2O + Cl2(i) HCl is oxidized to Cl2(ii) MnO2 is reduced to MnCl2(iii) MnCl2 acts as an oxidizing agent(iv) HCl acts as on oxidizing agent(ii), (iii) and (iv)(i), (ii) and (iii)(i) and (ii) only(iii) and (iv) only

Accepted Answer

(i) and (ii) onlyReason — The reaction is a redox reaction where, HCl is oxidized to Cl2 as it loses hydrogen whereas MnO2 is reduced to MnCl2 as it loses oxygen.

Question 8

Question 8Select from the following the statement which is true for bases.Bases are bitter and turn blue litmus red.Bases have a pH less than 7.Bases are sour and change red litmus to blue.Bases turn pink when a drop of phenolphthalein is added to them.

Accepted Answer

Bases turn pink when a drop of phenolphthalein is added to them.Reason — Phenolphthalein is a pH indicator which turns pink when added to a basic solution.

Question 9

Question 9Study the following table and choose the correct option:S.No.SaltParent AcidParent BaseNature of Salt(a)Sodium ChlorideHClNaOHBasic(b)Sodium CarbonateH2CO3NaOHNeutral(c)Sodium SulphateH2SO4NaOHAcidic(d)Sodium AcetateCH3COOHNaOHBasic

Accepted Answer

Sodium AcetateCH3COOHNaOHBasicReason — Sodium acetate made from acetic acid and sodium hydroxide is basic in nature.

Question 10

Question 10It is important to balance the chemical equations to satisfy the law of conservation of mass. Which of the following statements of the law is incorrect?The total mass of the elements present in the reactants is equal to the total mass of the elements present in the products.The number of atoms of each element remains the same, before and after a chemical reaction.The chemical composition of the reactants is the same before and after the reaction.Mass can neither be created nor can it be destroyed in a chemical reaction.

Accepted Answer

The chemical composition of the reactants is the same before and after the reaction.Reason — During the reaction, the chemical composition of the reactants change to form new products. Hence, this statement is incorrect.

Question 11

Question 11Consider the following statements in connection with the functions of the blood vessels marked A and B in the diagram of a human heart as shown.(i) Blood vessel A — It carries carbon dioxide rich blood from the lungs.(ii) Blood vessel B — It carries oxygen rich blood from the lungs.(iii) Blood vessel B — Left atrium relaxes as it receives blood from this blood vessel.(iv) Blood vessel A — Right atrium has thick muscular wall as it has to pump blood to this blood vessel.The correct statements are(i) and (ii) only(ii) and (iii) only(ii), (iii) and (iv)(i), (ii) and (iii)

Accepted Answer

(i), (ii) and (iii)Reason— Blood vessel A is Pulmonary artery that takes deoxygenated blood to lungs and Blood vessel B is Pulmonary vein that takes oxygenated blood from lungs to left atrium.

Question 12

Question 12In living organisms during respiration which of the following products are not formed if oxygen is not available?Carbon dioxide + WaterCarbon dioxide + AlcoholLactic acid + AlcoholCarbon dioxide + Lactic acid

Accepted Answer

Carbon dioxide + WaterReason — Carbon dioxide + Water is formed during aerobic respiration in presence of oxygen.

Question 13

Question 13The correct statements with reference to single celled organisms are:(i) Complex substances are not broken down into simpler substances.(ii) Simple diffusion is sufficient to meet the requirement of exchange of gases.(iii) Specialised tissues perform different functions in the organism.(iv) Entire surface of organism is in contact wih the environment for taking in food.(i) and (iii)(ii) and (iii)(ii) and (iv)(i) and (iv)

Accepted Answer

(ii) and (iv)Reason — In unicellular organisms respiration occurs by simple diffusion and they have entire cell surface to take food.

Question 14

Question 14Which one among the following is not removed as a waste product from the body of a plant?Resins and GumsUreaDry LeavesExcess water

Accepted Answer

UreaReason — Plants do not excrete urea. Urea is an animal waste product.

Question 15

Question 15Which of the following statements are correct in reference to the role of A (shown in the given diagram) during a breathing cycle in human beings?(i) It helps to decrease the residual volume of the air in lungs.(ii) It flattens as we inhale.(iii) It gets raised as we inhale.(iv) It helps the chest cavity to become larger.(ii) and (iv)(iii) and (iv)(i) and (ii)(i), (ii) and (iv)

Accepted Answer

(ii) and (iv)Reason — While breathing in, we lift our ribs and flatten our diaphragm, and the chest cavity becomes larger. Because of this, air is sucked into the lungs and fills the expanded alveoli.

Question 16

Question 16Which one of the following conditions is true for the state of stomata of a green leaf shown in given diagram?Large amount of water flows into the guard cells.Gaseous exchange is occurring in large amount.Large amount of water flows out from the guard cells.Large amount of sugar collects in the guard cells.

Accepted Answer

Large amount of water flows out from the guard cells.Reason — Large amount of water flows out from the guard cells making the cells flaccid. This closes the stomata. The stomata opens again when guard cells become turgid by taking in water.

Question 17

Question 17In which of the following is a concave mirror used?A solar cookerA rear view mirror in vehicles.A safety mirror in shopping malls.In viewing full size image of distant tall buildings.

Accepted Answer

A solar cookerReason — Large concave mirrors are used to concentrate sunlight to produce heat in solar cookers.

Question 18

Question 18A student wants to obtain a magnified image of an object AB as on a screen. Which one of the following arrangements shows the correct position of AB for him/her to be successful?1.2.3.4.

Accepted Answer

Reason — When the object is kept between F and 2F, enlarged, real and inverted image is obtained on the screen.

Question 19

Question 19The following diagram shows the use of an optical device to perform an experiment of light. As per the arrangement shown, the optical device is likely to be a;Concave mirrorConcave lensConvex mirrorConvex lens

Accepted Answer

Concave lensReason — As the rays are passing through the device so it should be a lens and as we can see that the rays are diverging, hence it is a concave lens.

Question 20

Question 20A ray of light starting from the air passes through medium A of refractive index 1.50, enters medium B of refractive index 1.33 and finally enters medium C of refractive index 2.42. If this ray emerges out in the air from C, then for which of the following pairs of media the bending of light is least?air-AA-BB-CC-air

Accepted Answer

A-BReason — The bending of light is least when the refractive index change is least. When light is travelling from medium A to medium B, the change in refractive index is from 1.50 to 1.33 which is the least in this case. Hence, the bending of light is also the least for A-B.

Solved 2022 Term 1 Question Paper CBSE Class 10 Science

Section A

Section B

Section C