Question

2. a. What volume of oxygen needed for the complete combustion of
20g of hydrogen? (N.B 1 mole = 22.4dm3

(volume))

b. What mass of water is produced from the reaction (2a) above?

Answer 1

Answer:

2H2 + O2 —-> 2H2O

From reaction,

2 moles H2 require 1 mole/ 22.4L O2

So let 20 moles (20g/1g) H2 require x moles O2

Then x = 20 * 22.4 / 2

x = 224L oxygen is required.

Mass water produced.:-

Since H2 and H20 have same coefficients in balanced reaction. They have same no of moles ie; 20 moles

Mass water = 20 * 18g = 360g

( Molar mass of water = 18g )