Jamb Chemistry 2019 Past Questions and Answers

Question 136:

• JAMB 2019

How many alkoxyalkanes can be obtained from the molecular formula C${}_4$H${}_{10}$O?

A. 4
B. 2
C. 1
D. 3

Question 137:

• JAMB 2019

The reaction $2H_{2}S+S{O}_2\to 3S+2H_{2}O$ is

A. Not a redox reaction because there is no oxidant in the reaction
B. Not a redox reaction because there is no reductant in the reaction
C. A redox reaction in which H${}_2$S is the oxidant and SO${}_2$ is the reductant
D. A redox reaction in which SO${}_2$ is the oxidant and H${}_2$S is the reductant

Question 138:

• JAMB 2019

A solution X, on mixing with AgNO${}_3$ solution gives a white precipitate soluble in aqueous NH${}_3$, a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain

A. Al${}^{3+}$, Cl${}^{-}$
B. Hg${}^{+}$, SO${}_4^{2-}$
C. Pb${}^{2+}$, Cl${}^{-}$
D. Ag${}^{+}$, SO${}_4^{2-}$

Question 139:

• JAMB 2019

How many electrons will be found in the nucleus of an atom with mass number 23 and 17 neutrons?

A. None
B. 6
C. 7
D. 8

Question 140:

• JAMB 2019

An element Z contains 80% of ${}_8^{16}$Z and 20% of ${}_8^{18}$Z. Its relative atomic mass is

A. 16.2
B. 17.6
C. 16.0
D. 16.4