Default Title

Question (1)

QN001121

Rusting of iron is considered a chemical change because

(A) iron melts slowly
(B) a new substance is formed
(C) only colour changes
(D) shape changes permanently

Correct Answer: B

Explanation:

Rusting forms a new substance called rust.

Link:

Report Error

Question (2)

QN001122

The brown substance formed during rusting is called

(A) iron sulphide
(B) iron carbonate
(C) rust
(D) magnesium oxide

Correct Answer: C

Explanation:

The brown coating formed on iron is rust.

Link:

Report Error

Question (3)

QN001123

Rust is chemically known as

(A) iron oxide
(B) iron sulphate
(C) iron chloride
(D) calcium oxide

Correct Answer: A

Explanation:

Rust is mainly iron oxide.

Link:

Report Error

Question (4)

QN001124

Which of the following is an example of combustion?

(A) Folding paper
(B) Burning magnesium ribbon
(C) Melting ice
(D) Breaking glass

Correct Answer: B

Explanation:

Burning magnesium ribbon is a combustion reaction.

Link:

Report Error

Question (5)

QN001125

When magnesium ribbon burns in air, it produces

(A) magnesium chloride
(B) magnesium carbonate
(C) magnesium oxide
(D) magnesium nitrate

Correct Answer: C

Explanation:

Magnesium reacts with oxygen to form magnesium oxide.

Link:

Report Error

Question (6)

QN001126

The white powder formed after burning magnesium ribbon is

(A) magnesium sulphate
(B) magnesium oxide
(C) calcium carbonate
(D) sodium carbonate

Correct Answer: B

Explanation:

Burning magnesium forms white magnesium oxide powder.

Link:

Report Error

Question (7)

QN001127

Which observation confirms that burning magnesium is a chemical change?

(A) Ribbon becomes smaller
(B) New substance is formed with heat and light
(C) Shape changes only
(D) Ribbon evaporates

Correct Answer: B

Explanation:

Heat, light, and a new substance indicate chemical change.

Link:

Report Error

Question (8)

QN001128

Combustion is a chemical reaction in which a substance reacts with

(A) hydrogen
(B) nitrogen
(C) oxygen
(D) helium

Correct Answer: C

Explanation:

Combustion occurs in the presence of oxygen.

Link:

Report Error

Question (9)

QN001129

Which of the following is a combustible substance?

(A) Stone
(B) Wood
(C) Water
(D) Sand

Correct Answer: B

Explanation:

Wood burns easily in air.

Link:

Report Error

Question (10)

QN001130

During combustion, substances generally produce

(A) only sound
(B) heat and/or light
(C) only smoke
(D) magnetic effect

Correct Answer: B

Explanation:

Combustion releases energy in the form of heat and light.

Link:

Report Error

Question (1)

Rusting of iron is considered a chemical change because

Explanation:

Link:

Question (2)

The brown substance formed during rusting is called

Explanation:

Link:

Question (3)

Rust is chemically known as

Explanation:

Link:

Question (4)

Which of the following is an example of combustion?

Explanation:

Link:

Question (5)

When magnesium ribbon burns in air, it produces

Explanation:

Link:

Question (6)

The white powder formed after burning magnesium ribbon is

Explanation:

Link:

Question (7)

Which observation confirms that burning magnesium is a chemical change?

Explanation:

Link:

Question (8)

Combustion is a chemical reaction in which a substance reacts with

Explanation:

Link:

Question (9)

Which of the following is a combustible substance?

Explanation:

Link:

Question (10)

During combustion, substances generally produce

Explanation:

Link:

Excel With Tutors

ExcelWithTutors

For Student

For Tutors

Learn

OUR POLICY