Post Utme Chemistry Past Questions and Answers

Question 301:

A molecular formula shows ____________ in a molecule.

A. The elements present
B. The number of atoms of each element
C. Cations and anions
D. Chemical symbols and number of atoms

Question 302:

Give the total mass of copper in 1 gram of copper (II) sulphate [Cu = 40, S = 32, 0=16]

A. 025g
B. 050g
C. 10g
D. 25g

Question 303:

\({ }^{14}{ }_{55} \mathrm{Cs} \rightarrow \frac{\mathrm{A}}{\mathrm{Z}}+{ }_{2}^{4} \alpha\). Find the value of \(A\) and \(Z\) in the equation above.

A. 119,53
B. 110,57
C. 110,53
D. 110,58

Question 304:

How many moles of \(\mathrm{H}_{2}\) molecules are needed to convert 5 mole of \(\mathrm{O}_{2}\) molecules to water?

A. 5 mole \(\mathrm{H}^{2}\)
B. 10 mole \(\mathrm{H}^{2}\)
C. 15 mole \(\mathrm{H}_{2}\)
D. 20 mole \(\mathrm{H}_{2}\)

Question 305:

\({ }_{88}^{226} R a \rightarrow \frac{\mathrm{A}_{\mathrm{Z}}}{R n}+\mathrm{a}\). What is the value of \(x\) in the nuclear reaction above?

A. 220
B. 222
C. 226
D. 227