NECO Chemistry Past Questions & Answers - Page 25

121.

Which is NOT a synthetic polymer?

A.

nylon

B.

Orion

C.

Perspex

D.

polystyrene

E.

wool

Correct answer is E

No explanation has been provided for this answer.

122.

The reaction C2H6 → C2H + H2 is known as

A.

dehydration

B.

dehydrogenation

C.

displacement

D.

hydrogenation

E.

reduction

Correct answer is B

No explanation has been provided for this answer.

123.

The boiling point of water is higher than the boiling point of ethanol because

A.

the bonding in water is electrovalent (ionic) whereas the bonding in ethanol is convalent

B.

the hydrogen bonding between water molecules is stronger than the hydrogen bonding between ethanol molecules

C.

water has a higher lattice energy than ethanol.

D.

water has hydrogen bonding between its molecules but ethanol has no hydrogen bonging between its molecules;

E.

water is a better solvent than ethanol.

Correct answer is B

No explanation has been provided for this answer.

124.

B is an isotope of the element \(^{238} _{92}Ur\). The isotope B has

A.

46 protons and 119 neutrons

B.

92 protons and 92 neutrons

C.

92 protons and 146 neutrons

D.

92 protons and 238 neutrons

Correct answer is C

No explanation has been provided for this answer.

125.

The number of hydrogen ions in 1.0dm6.00x103 of a 0.25 mole dm6.00x10-3 tetraoxosulphate(Vl) acid solution is
[Avogadro constant = 6.0 x 1 0]

A.

1.45x1023

B.

1.50 x l023

C.

3.00x1023

D.

3.15x1023

E.

6.00x1023

Correct answer is B

No explanation has been provided for this answer.