Jamb Chemistry 2020 Past Questions and Answers

Question 16:

• JAMB 2020

How many valence electrons are contained in the element ${}_{15}^{31}P$?

A. 3
B. 4
C. 15
D. 31

Question 17:

• JAMB 2020

The number of molecules of Carbon(iv)Oxide produced when 10.0g of CaCO${}_3$ is treated with 0.2dm${}^3$ of 1 Mole of HCL in the equation
CaCO${}_3$ + 2HCL ⇒ CaCl${}_2$ + H${}_2$ O + CO${}_2$ , is ?

A. 1.00 X 10${}^{23}$
B. 6.02 X 10${}^{23}$
C. 6.02 X 10${}^{22}$
D. 6.02 X 10${}^{24}$

Question 18:

• JAMB 2020

The volume occupied by 1.58g of a gas at S.T.P is 500cm${}^3$. What is the relative molecular mass of the gas? [ G.M.V at S.T.P = 22.4dm${}^3$ ]

A. 28
B. 32
C. 44
D. 71

Question 19:

• JAMB 2020

Which of the following gases will rekindle a brightly splint?

A. NO${}_2$
B. NO
C. N${}_2$O
D. CL${}_2$

Question 20:

• JAMB 2020

The shape of ammonia molecule is?

A. Trigonal planar
B. Octahedral
C. Square planar
D. Tetrahedral