Post Utme Chemistry Past Questions and Answers

Question 541:

Elements X and Y have electronic configurations 1s²²s²²p⁴ and 1s²²s²²p⁶³s² when they combine; formula of the compound formed is ____________

A. XY
B. X2Y4
C. XY2
D. YX

Question 542:

The atomic number of an element is 55 and its atomic mass is 133. the nucleus of the atom therefore contains

A. 78 protons and 55 neutrons
B. 55 protons and 78 neutrons
C. 55 protons and 78 electrons
D. 78 protons and 55 neutrons

Question 543:

Which of the following would support the conclusion that a solid sample is a mixture ____________

A. The Solid can be ground to a fine powder
B. The density of the solid is 2.25gdn
C. The solid has a melting point range of 3000C TO 375^oC
D. The solid is hygroscopic

Question 544:

What is the partial pressure of hydrogen gas collected over water at standard atmospheric and 250C if the saturation vapour pressure of water is 23mmhg at that temperature?

A. 737mmHg
B. 763mmHg
C. 777 mmHg
D. 783mmHg

Question 545:

The mole ratio of carbon and hydrogen of a volatile liquid compound is 1:2.0.12g of the liquid on evaporationt at s.t.p gave 32cm³ of vapour.
The molecular formula of the liquid is ____________
[GMV = 22.4DM3)]

A. C3H8
B. C4H8
C. C5H10
D. C6H12