Question

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

Answer 1

I'm not completely sure but I think it is 27.4572. Hope I helped a little.

Answer 2

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
`H_2O`.

`\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