Percentage Composition of Compounds

What is the general formula for the computation of percentage composition of the given element?

• % mass of element = mass of element in the compound divided by mass of the compound times 100

• % mass of element = mass of element in the compound divided by mass of the compound

• % mass of element = mass of element in the compound divided by 100

• % mass of element = mass of element in the compound

What is the percent by mass of magnesium in MgO?

• 20%

• 40%

• 50%

• 60%

What is the percent by mass of chlorine in NaCl?

• 39%

• 61%

• 35%

• 35%

Tags

NGSS.MS-PS1-1

How would you calculate the percentage of Hydrogen?

d

c

a

18

100

2

16

Tags

NGSS.MS-PS1-1

What is the equation for calculating percent composition?

• mass of element/mass of compound = x 100

• mass of compound/mass of element = x 100 

• total mass/molar mass = x 100 

• molar mass/molar mass = x 100 

How would you calculate the percentage of Lithium?

d

c

a

87

100

7

80

How would you calculate the percentage of Magnesium?

a

b

d

100

56.31

24.3

32

The percent, by weight, of carbon in C₄H₈O₃ is (a)   .

• 55%

• 72%

• 31%

• 46%

(Page 38-40) Percent Composition is the ​ (a)   by ​ (b)   of each element in a compound.

• percentage

• mass

• compound

How would you calculate the percentage of Oxygen?

d

c

b

2

18

100

16