Ethanol (density = 0.789 g/ml) combusts and produces 34.8 g h2o. what was the original volume of the ethanol?

Question

asked Jul 26, 2019 228k views

2 Answers

Mouradif · Answer 1 · 2019-07-30T22:30:05+0000

Answer : The original volume of the ethanol is 37.5 mL

Explanation :

The balance chemical reaction will be,

$C2H_5OH+3O_2\rightarrow 2CO_2+3H_2O$

First we have to calculate the moles of
.

$\text{ Moles of }H_2O=\frac{\text{ Mass of }H_2O}{\text{ Molar mass of }H_2O}=(34.8)/(18g/mole)=1.93moles$

Now we have to calculate the moles of ethanol.

From the balanced reaction we conclude that,

As, 3 moles of
H_2O produce from 1 mole of ethanol

So, 1.93 moles of
H_2O produce from
(1.93)/(3)=0.643 mole of ethanol

Now we have to calculate the mass of ethanol.

$\text{ Mass of ethanol}=\text{ Moles of ethanol}* \text{ Molar mass of ethanol}$

$\text{ Mass of ethanol}=(0.643moles)* (46g/mole)=29.6g$

Now we have to calculate the volume of ethanol.

Density=(Mass)/(Volume)

0.789g/mL=(29.6g)/(Volume)

Volume=(29.6g)/(0.789g/mL)=37.5mL

Therefore, the original volume of the ethanol is 37.5 mL