Answer:
i) 0,7 molH20/s
ii)11,2 g O/s
iii)1,4 g H/s
Explanation:
i) To find the molar flow rate of water, we just convert the mass of water to moles of water using its molecular weight(g/mol) and changing to the proper units (lb to grames and hours to seconds):

ii) Now we just consider the oxygen in the water stream (for 1 mole of water there is 1 mole of oxygen):

iii)Just considering the hydrogen in the stream (for 1 mole of water there is 2 moles of hydrogen):

Answer: 72 grams of
are needed to completely burn 19.7 g 
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to molecular mass and contains avogadro's number
of particles.
To calculate the number of moles, we use the equation:

Putting in the values we get:


According to stoichiometry:
1 mole of
requires 5 moles of oxygen
0.45 moles of
require=
moles of oxygen
Mass of 
72 grams of
are needed to completely burn 19.7 g 
The awnser is D or the 4th one
...............................................c