Jamb Chemistry 2018 Past Questions and Answers

Question 31:

• JAMB 2018

An aqueous solution of a metal salt, M. gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia Therefore the cation in M is

A. Zn
B. Ca
C. Al
D. Po

Question 32:

• JAMB 2018

What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O =16, H = 1]

A. 0.40 moldm\(^{-3}\)
B. 0.50 moldm\(^{-3}\)
C. 0.05 moldm\(^{-3}\)
D. 0.30 moldm\(^{-3}\)

Question 33:

• JAMB 2018

How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 \(^{23}\)mol]

A. 1.20 x 10\(^{22}\)
B. 2.4 x 10\(^{22}\)
C. 1.51 x 10\(^{22}\)
D. 3.02 x 10\(^{22}\)

Question 34:

• JAMB 2018

The radio isotope used in industrial radiography for the rapid checking of faults in welds and casting is?

A. Carbon-14
B. Phosphorus-32
C. Cobalt
D. Iodine-131

Question 35:

• JAMB 2018

Beryllium and Aluminium have similar properties because they

A. Are both metals
B. Belong to the same group
C. Belong to the same period
D. Are positioned diagonally to each other