Science Class 8th

401. When _____ is heated at very high temperature CO2 and CaO are formed.

A) Sulpher Oxide

B) Marble

C) Cement

D) Calcium  Carbonate

402. During a chemical reaction heat is ______.

A) Absorbed

B) Released

C) Both A and B

D) None of the above

403. Heat evolved or absorbed during a chemical reaction is called the ______.

A) Specific Heat

B) Heat Capacity

C) Heat of Reaction

D) Total Heat

404. There are ____ types of reaction with respect to the energy changes.

A) Two

B) Three

C) Six

D) Seven


405. Chemical reactions in which heat is released.

A) Endothermic

B) Exothermic

C) Both A  and B

D) None of the above

406. Chemical reactions in which heat is absorbed.

A) Endothermic

B) Exothermic

C) Both A and B

D) None of the above

407. Which of the following occurs at the SUN:

A) Endothermic Reaction

B) Exothermic Reactions

C) Both A and B

D) None of the above

408. Breakdown of glucose inside the body is an _____ reaction.

A) Endothermic

B) Exothermic

409. Rusting of iron is an example of chemical reaction:

A) True

B) False

410. Symbols is the best way to express a chemical reaction:

A) True

B) False

411. What changes occur in the solution of AgNO3 and NaCl in the presence of sunlight.

A) Gas Evolved

B) Heat is produced

C) Precipitate is formed

D) No Change is observed

412. The total energy of the product in an ______ reaction is less than that of the reactant.

A) Exothermic

B) Endothermic

C) Both A and B

D) Addition

413. When Iron rusts, it reacts with:

A) Carbon

B) Oxygen in the Air

C) Nitrogen in Air

D) Chlorine

414. Common Table Salt:

A) Sodium Chloride

B) Calcium Carbonate

C) Magnesium Carbonate

D) None of the above

415. Which of the following is present in vinegar?

A) Lactic Acid

B) Acetic Acid

C) Hydrochloride Acid

D) Citric Acid

416. There are _____ main types of chemical compounds.

A) Two

B) Three

C) Four

D) Five

417. The _____ taste in fruits is due to acids.

A) Salty

B) Sugary

C) Bitter

D) Sour

418. The word acid is derived from a ______ word.

A) English

B) Roman

C) French

D) Latin

419. Alkalis are sweet in taste and rough in touch.

A) True

B) False

420. Salts are formed by the reaction of acids and alkalis.

A) True

B) False