JAMB Chemistry Past Questions & Answers - Page 83

411.

Diamond cannot be used

A.

In making bicycle chains

B.

As abrasives

C.

In cutting glass and metals

D.

As dies for drawing wires

Correct answer is A

No explanation has been provided for this answer.

412.

What volume of 0.5M H2SO4 will exactly neutralize 20cm3 of 0.1M NaOH Solution?

A.

2.0cm 3

B.

5.0cm 3

C.

6.8cm 3

D.

8.3cm 3

Correct answer is A

The balanced equation is given as:

\(H_{2}SO_{4} + 2NaOH \to Na_{2}SO_{4} + 2H_{2}O\)

Molarity of \(NaOH = 0.1M\)

Volume of \(NaOH = 20cm^{3}\)

Molarity of \(H_{2}SO_{4} = 0.5M\)

mol NaOH = \(0.1 \times 20cm^{3} = 2molNaOH\)

⇒ \(2mol NaOH \times \frac{1mol H_{2}SO_{4}}{2mol NaOH} = 1 mol H_{2}SO_{4}\)

\(volume of H_{2}SO_{4} = \frac{mole of H_{2}SO_{4}}{molarity of H_{2}SO_{4}}\)

= \(\frac{1 mole}{0.5 M} = 2cm^{3} H_{2}SO_{4}\)

413.

An example of an acidic oxide is

A.

NO

B.

CO

C.

SO2

D.

CuO

Correct answer is C

No explanation has been provided for this answer.

414.

The metal whose ore can be concentrated by passing it through a magnetic separator is

A.

Zn

B.

Sn

C.

Cu

D.

Ca

Correct answer is B

No explanation has been provided for this answer.

415.

Which of the following statements is correct about the periodic table?

A.

Elements in the same group have the same number of electron shells

B.

The non-metallic properties of the elements tend to decrease across each period

C.

Elements in the same period have the same number of valence electrons

D.

The valence electrons of the elements increase progressively across the period

Correct answer is D

No explanation has been provided for this answer.