Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

1,216.

A substance is said to be hygroscopic if it absorbs

A.

water from the atmosphere to form a solution

B.

heat from the surrounding

C.

carbon (IV) oxide from the atmosphere

D.

moisture from the atmosphere without dissolving

Correct answer is D

No explanation has been provided for this answer.

1,217.

Which of following acids forms normal salts only?

A.

Tetraoxosulphate (VI) acid

B.

Trioxosulphate (IV) acid

C.

Acetic acid

D.

Tetraoxophosphate (V) acid

Correct answer is C

So we can determine that the basicity of Acetic acid is 1 because it releases one hydrogen ion in an aqueous solution.

Due to this they act as very weak acids. When weak acid reacts with strong base, they tend to form normal salt.

1,218.

A major factor considered in selecting a suitable method for preparing a simple salt is its

A.

crystalline form

B.

melting point

C.

reactivity with dilute acids

D.

solubility in water

Correct answer is D

No explanation has been provided for this answer.

1,219.

The gas given off when NH4 Cl is heated with an alkali is

A.

H2

B.

Cl2

C.

N2

D.

NH3

Correct answer is D

No explanation has been provided for this answer.

1,220.

Determine the mass of sulphur (IV) oxide obtained when 91.0g of oxygen reacts completely with sulphur according to the following equation: S(s) + O\(_2\)(g) → SO\(_2\)(g) [S = 32; O = 16]

A.

123g

B.

139g

C.

155g

D.

182g

Correct answer is D

S + O\(_2\) → SO\(_2\).

According to the equation 32g of O\(_2\) produced 64g of SO\(_2\)

therefore 91g of O2 will produce yg of SO2
y = \(\frac{91 * 64}{32}\)

y = 182g of SO\(_2\)