Answer:
162g
Step-by-step explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2C2H6 + 7O2 —> 4CO2 + 6H2O
Next, we shall determine the number of mole of water, H2O produced by the reaction of 3 moles of C2H6.
This can be obtained as follow:
From the balanced equation above,
2 moles of C2H6 reacted to produce 6 moles of H2O.
Therefore, 3 moles of C2H6 will react to produce = (3 x 6)/2 = 9 moles of H2O.
Therefore, 9 moles of H2O is produced from the reaction.
Finally, we shall convert 9 moles of H2O to grams.
This can be done as shown below:
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mole of H2O = 9 moles
Mass of H2O =..?
Mole = mass / molar mass
9 = mass of H2O /18
Cross multiply
Mass of H2O = 9 x 18
Mass of H2O = 162g
Therefore, 162g of H2O were produced from 3 moles of C2H6.