WorksheetsPOST TEST: PERCENTAGE COMPOSITION
Total questions: 10
Worksheet time: 6mins
The label of the dark chocolate indicates that its mass is 150g and it is 70%
cacao, if you consume the whole chocolate bar, how much cacao did you eat?
A. 105 g cacao
B. 45 g cacao
C. 100 g cacao
D. 50 g cacao
It means a part per hundred.
mole
grams
percentage
molar mass
It is often represented by grams per mole (g/mol) and is the total mass of one mole of a substance .
atomic mass
molecular mass
formula mass
molar mass
A bag of NPK fertilizer marked 16-4-8 contains 16% nitrogen, 4%
phosphorous and 8% potassium, the other 72% is usually inert filler
material, such as clay pellets or granular limestone. What is the mass of
nitrogen present in 500g pack of NPK fertilizer?
80g
20g
40g
10g
The presence of SO2 in the atmosphere causes acid rain. How many percent of sulfur is present in SO2 (S= 32.07, 0=16.00; Molar Mass = 64.07g/mole)?
40.00%
49.95%
60.00%
50.05%
In cold areas, many fish and insects, including the common housefly, produce large amounts of glycerol (C3H8O3 Molar Mass = 92.11 g/mole) to lower the freezing point of their blood. How many percent of oxygen is present in glycerol?
(C= 12.01, H= 1.01, O=16.00)
52.11%
50.11%
51.11%
53.11%
It is the ratio of the mass of an element compared to the compound’s mass.
Molar Mass
Percentage Composition
Molar Concept
Molecular Mass
Who among these chemists and physicists made use of the mole concept to
represent the number of particles in a substance?
A. Amedeo Avogadro
B. Jacques Charles
C. John Dalton
D. Robert Boyle
Which of these values is the correct molar mass for Sodium chloride (NaCl)?
(Na= 22.99, Cl= 35.45)
A. 58.4 g/mol
B. 45.2 g/mol
C. 38.1 g/mol
D. 11.3 g/mol
What do you expect to observe in a “Mole Exhibit of Different Substances?
different kind of elements
different colors of substances
showcase of 1mole of different elements having different masses
showcase of 1mole of different substances having the same masses
