what is the mass of H2O produced when 10.0 grams of H2 reacts completely with 80.0 grams of O2? A(70.0 grams) B(90.0 grams) C(180.0 grams) C(800.0 grams)

Chemistry · High School · Thu Feb 04 2021

Answered on

Chemical reaction: 

2H2 + O2  ----- > 2H2O

Mass of hydrogen, M= 2g/mol

Mass of hydrogen substance, m = 10 g

n = m/M

= 10/2

= 5 mol

Mass of O2, M = 32 g/mol 

Mass of O2 substance = 80 grams

n = 80/32

= 2.5 mol

So, Mass of H2O produced = 10 + 80 g

= 90 g

So, option (B) is correct.