Chemistry Past Questions and Answers

Which of the following methods can be used to seperate blood cells from plasma?

A Centrifugation
B Filtration
C Chromatography
D Distillation

Question 1477:

Which of the following statements is true about ionic radius? Ionic radius

A Increases as nuclear charge increases
B Decreases as nuclear charge increases
C Decreases as nuclear charge decreases
D Remains constant as nuclear charge increases

Question 1478:

Analysis of a hydrocarbon shows that it contains 0.93g of Carbon per gram of the compound. The mole ratio of carbon to hydrogen in the compound is [H = 1.0, C=12.0]

A 1:1
B 1:2
C 2:1
D 2:3

Question 1479:

The law of definite proportions states that

A Pure samples of the same compound contain the same elements combined in the same proportion by mass
B Pure samples of substances are in the same proportion by mass
C Chemical compounds are pure because they contain the same elements
D Matter can neither be created nor destroyed.

Question 1480:

What is the relative molecular mass of a compound which has empirical formula \(CH_{2}O\)? [C= 12, H= 1, O= 16]

A 42
B 45
C 126
D 180