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.

436.

Which of the gas laws does this graph illustrate?

Boyle

Charles

Gay-Lussac

Graham

View answer & explanation

Correct answer is B

Charles' law describes the effect of temperature changes on the volume of a given mass of gas at a constant pressure.

437.

The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?

with cool running water

sodium hydroxide solution

iodine solution

sodium trioxonitrate(v) solution

View answer & explanation

Correct answer is A

Sulfuric acid is flushed with a mild, soapy solution if the burns are not severe. Sulfuric acid feels hot when water is added to the acid, but it is better to flush the area and not leave the acid on the skin.
Don't try to neutralize the burn with acid or alkali. This could cause a chemical reaction that worsens the burn.

438.

8g of CH\(_4\) occupies 11.2 at S.T.P. What volume would 22g of CH\(_3\)CH\(_2\)CH\(_3\) occupy under the same condition?

3.7dm\(^3\)

11.2dm\(^3\)

22.4dm\(^3\)

33dm\(^3\)

View answer & explanation

Correct answer is B

Molar mass of methane = 16g/mol

At S.T.P. its 8g occupies 11.2

so 16g occupies 22.4 dm\(^3\)

Molar mass of propane = 44g/mol\(^-1\) occupies 22.4dm\(^3\) at S.T.P

so 22g will occupy 11.2dm\(^3\)

439.

An example of a polysaccharide is?

Dextrose

Mannose

Glucose

Starch

View answer & explanation

Correct answer is D

Polysaccharides are long chains of monosaccharides linked by glycosidic bonds. Three important polysaccharides, starch, glycogen, and cellulose, are composed of glucose.