Answer to Question #108738 in General Chemistry for Joy

Question

Determine the simplest formula of compounds whose composition are given
a)0.795g of an oxide of copper having been reduced to 0.635g of copper by heating in a stream of hydrogen
b)a compound that contains 27.38%sodium 1.19%hydogen 14.20%carbon and 57.15% oxygen
c)a compound that contains 29.41% calcium 23.53% sulphur and 47.06%oxygen
d)1.39 ofcrystalline salt that contains 0.28g iron 0.16g sulphur 0.32g oxygen and 0.63g water of crystalline
e)1.00g of a compound that contains 0.40g calcium

Answer 1

a) CuxOy + H₂ = Cu + H₂O

0.635/0.795=0.7987=79.87

79.87/63/546=1.256

100%-79.87=20.13

79.87/63.546=20.13/x

x=16.02

CuO

b)Na_xH_yC_uO_z

$\frac{27.38}{22.98977}=\frac{1.19}{1.00794}=\frac{14.20}{12.011}=\frac{57.15}{15.9994}=1.1909645=1.18062583=1.1822496=3.5720895=1:1:1:3$

NaHCO3 sodium bicarbonate

c)СaxSyOz

$\frac{29.41}{40.08}=\frac{23.53}{32.06}=\frac{47.26}{15.9994}=0.7337=0.7339=2.95386077=1:1:4$

СaSO4 calcium sulfate

d) 0.28/1.39=20.14

0.16/1.39=11.51

0.32/1.39=23.02

0.63/1.39=45.33

$\frac{20.14}{55.847}=\frac{11.51}{32.06}=\frac{23.02}{15.994}=\frac{45.33}{18.01528}=0.3606=0.3590=1.439=2.5162=1:1:4:7$

FeSO4*7H2O Iron sulfate (II)

e)0.40/1.0=0.4=40% 100-40=60

40/40.08=60/x

x=60.12

60.12+40.08=100.2

CaCO3 - calcium carbonate