If 250g of sugar is completely fermented to ethanol, what is the theoretical yield of ethyl alcohol in: ?
i. grams or milliliters (density of ethanol is 0.79g/mL)
ii. what is the final %v/v of alcohol if that 250 sugar was used to make 1L of wine? (assume no volume changed during fermentation)
please, show me the working out.
Thanks
i. grams or milliliters (density of ethanol is 0.79g/mL)
ii. what is the final %v/v of alcohol if that 250 sugar was used to make 1L of wine? (assume no volume changed during fermentation)
please, show me the working out.
Thanks
2 Answers
Here's what I got.
Explanation:
Start by writing the chemical equation that describes this reaction
#"C"_ 6"H"_ 12"O"_ (6(aq)) -> 2"C"_ 2"H"_ 5"OH"_ ((aq)) + 2"CO"_ (2(g)) uarr#
SIDE NOTE As you can see, I am assuming that by
If you were supposed to work with sucrose instead of glucose, add this step
#"C"_ 12"H"_ 22"O"_ (11(aq)) + "H"_ 2"O"_ ((l)) -> 2"C"_ 6"H"_ 12 "O"_ (6(aq))#
and redo the calculations with the mass of glucose that you'll get from this reaction.
Now, notice that you have a
#250 color(red)(cancel(color(black)("g"))) * "1 mole glucose"/(180.156color(red)(cancel(color(black)("g")))) = "1.388 moles glucose"#
This means that the reaction will produce
#1.388 color(red)(cancel(color(black)("moles glucose"))) * "2 moles ethanol"/(1color(red)(cancel(color(black)("mole glucose")))) = "2.776 moles ethanol"#
To convert this to grams, use the molar mass of ethanol
#2.776 color(red)(cancel(color(black)("moles ethanol"))) * "46.07 g"/(1color(red)(cancel(color(black)("mole ethanol")))) = "127.9 g"#
Rounded to two sig figs, the answer will be
#color(darkgreen)(ul(color(black)("theoretical yield = 130 g")))#
To convert this to milliliters, use the density of ethanol
#127.9 color(red)(cancel(color(black)("g"))) * "1 mL"/(0.79color(red)(cancel(color(black)("g")))) = color(darkgreen)(ul(color(black)("160 mL")))#
To find the volume by volume percent concentration of the wine,
Now, the solution's volume by volume percent concentration tells you the volume of solute present for every
In your case,
#100 color(red)(cancel(color(black)("mL solution"))) * "160 mL ethanol"/(10^3color(red)(cancel(color(black)("mL solution")))) = "16 mL ethanol"#
Therefore, the concentration by volume will be
#color(darkgreen)(ul(color(black)("% v/v = 16% ethanol")))#
I'll leave the answer rounded to two sig figs, but don't forget that you only have one significant figure for the volume of wine.
i. The theoretical yield of ethanol is 135 g or 170 mL; ii.the final concentration is 17 % v/v.
Explanation:
We know that we will need a balanced equation with masses and moles, so let's gather all the information in one place.
I assume that by "sugar" you mean sucrose,
Step 1. Calculate the moles of sugar
Step 2. Calculate the moles of ethanol
Step 3. Calculate the mass of ethanol
Step 4. Calculate the volume of ethanol
Step 5. Calculate the volume % of ethanol