Water can be formed from the stoichiometric reaction of hydrogen with oxygen: #2H_2(g) + O_2(g) + 2H_2O(g)#. A complete reaction of 5.0 g of #O_2# with excess hydrogen produces how many grams of #H_2O#?

1 Answer
Jan 16, 2017

Your equation specifies that #32*g# of dioxygen and #4*g# of dihydrogen give #36*g# of water upon reaction, so..........

Explanation:

#2H_2(g) + O_2(g) rarr 2H_2O(g)#

We started with #(5.0*g)/(32.00*g*mol^-1)=0.156*mol" dioxygen"#.

Given excess dihydrogen, this molar quantity thus gives #2xx0.156*mol# water.

And thus, #2xx0.156*molxx18.01*g*mol^-1~=6*g# water are evolved. Is this reaction exothermic or endothermic?