Question

question 1 Calculate all

a)Calculate the empirical formula of each compound from the percent composition.

86.0 %Cu and 14.0 %P

Express your answer as a chemical formula.

b)25.9 %N and 74.1 %O

c)Calculate the empirical formula for each of the following substances.4.22 g of Na, 2.94 g of S, and 5.86 g of O

d)Calculate the mass percent composition of each of the following:4.12 g of C, 0.695 g g of H, and 2.76 g g of O,3.38 g of N, 0.810 g of H, and 3.91 g of S

Answer 1

a)
Let total mass be 100 gm.
Cu: 86.00 g
P: 14.00 g

Divide by molar mass to get number of moles of each:
Cu: 86.00/63.5 = 1.35
P: 14.00/31.0 = 0.45

Divide by smallest to get simplest whole number ratio:
Cu: 1.35/0.45 = 3
P: 0.45/0.45 = 1

So empirical formula is:Cu3P
please check the whole number

b)
Let total mass be 100 gm.
N: 25.90 g
O: 74.10 g

Divide by molar mass to get number of moles of each:
N: 25.90/14.0 = 1.85
O: 74.10/16.0 = 4.63

Divide by smallest to get simplest whole number ratio:
N: 1.85/1.85 = 1
O: 4.63/1.85 = 2.5

get whole number:
N : 1*2 = 2
O : 2.5*2 = 5

So empirical formula is:N2O5

Please solve rest similarly