Question

135.0  g of NH3 is mixed with 219.6 g of O2 and allowed to react. The reaction is complete when the NH3 is consumed.  111.1 g of N2 is formed and 29.40 g O2 remain unreacted. What mass of H2O is produced?

Answer 1

4NH3 + 3O2 = 2N2 +6H2O

1 MOLE NH3 WEIGHS = 17 GRAMS

1 GRAM NH3 IS = 1/17 MOLES OF NH3

135 GRAMS NH3 IS = 1/17 * 135 = 7.94 MOLES OF NH3

1 MOLE O2 WEIGHS = 16*2 = 32 GRAMS

1 GRAM O2 IS 1/32 MOLES

219.6 GRAMS O2 IS = /32 * 219.6 = 6.86 MOLES

1 MOLE N2 WEIGHS 14*2 = 28 GRAMS

1 GRAM IS = 1/28 MOLES N2

111.1 GRAM N2 IS = 111.1 * 1/28 = 3.96 MOLES

AND FINALLY 1 MOLE H2O WEIGHS 18 GRAMS

SO IN THE GIVEN BALANCED REACTION

4 MOLES OF NH3 REACT WITH 3 MOLE O2 TO GIVE 2 MOLE N2 AND 6 MOLE H2O

NH3 IS CONSUMED TOTALLY SO IF 1MOLE NH3 IS CONSIDERED THEN 3/4 MOLES OF O2 REACTS AND GIVES 2/4 MOLE N2 AND 6/4 MOLE H2O

WE ARE GIVEN WITH 7.94 MOLE NH3

SO 7.94 MOLE NH3 REACTS WITH (3/4 * 7.94=5.95 ) MOLES O2 TO GIVE (2/4 * 7.96 = 3.98 MOLES N2) AND ( 6/4 * 7.96 = 11.94 ) MOLES H20

1 MOPLE H2O WEIGHS 18 GRAMS

11.94 MOLES H2O WEIGHS 214.92 GRAMS H2O