Answer to Question #123533 in General Chemistry for Medina

Question

a) When 2.00 g of lead is heated with sulfur, 2.30 g of lead (II) sulfide is formed. Calculate the percent composition by mass of each element in lead (II) sulfide.

b)A lab technician find that an 11.5 g of a liquid compound contains 6.00 g of carbon and
1.51 g of hydrogen. The remaining mass is oxygen. Determine the percentage composition
of the compound

c)Calculate the percent composition by mass of all elements in the compound
(NH4 ) 2CO3

Answer 1

2 grams of lead

2.30 grams of lead (II) sulfide formed

A) lead = (2/2.3)(100)

= 86.95 %

Sulfur = ( 0.30/ 2.30) (100)

= 13.04 %

B) 11.5 grams in a liquid

6 grams of carbon

= (6/11.5)(100)

= 52.17%

1.51grams of hydrogen

=( 1.51/11.5)(100)

= 13.13%

3.99 grams of oxygen

= (3.99/11.5)(100)

= 34.70%

C) mass of ammonium carbonate is equal to 96.09g

(NH₄ )₂ CO₃ = 96.09 grams

N = (28/96.09)(100)

= 29.14%

H = (8/96.09)(100)

= 8.33%

C = (12/96.09)(100)

= 12.49%

O = (48/96.09)(100)

= 49.95%