WorksheetsW2 July Sec CS-S3A Mole Concept 1
Total questions: 5
Worksheet time: 3mins
Which is the correct symbol of the isotope of carbon that is used to standardise the relative atomic mass, Ar, of an atom?
11C
12C
13C
14C
An element X is found in its natural state on earth as two isotopes, 63X and 65X.
It is estimated that 69.2% of X on earth is found as 63X.
What is the relative atomic mass, Ar, of element X?
63.0
63.6
64.5
65.0
Ethanoic acid has the molecular formula CH3COOH. What is the relative molecular mass of ethanoic acid?
55 g
55
60 g
60
Ammonium sulfate has the molecular formula (NH4)2SO4. What is the relative formular mass of ammonium sulfate?
128 g
128
132 g
132
The element chlorine, Cl, forms a yellowish-green gas and is found as a diatomic molecule in its natural state.
Using Avogadro’s constant, how many chlorine atoms are present in 0.25 moles of chlorine gas?
1.5 x 1023 atoms
2 x 1023 atoms
3 x 1023 atoms
6 x 1023 atoms
