Hey guys, I need some help with chemistry.
1. Is the reaction when ethanol is burned in oxygen exothermic? Explain why / why not.
2. What is the concentration of hydrochloric acid solution if you mixed 0.14 liters, 2 mol / dm 3 hydrochloric acid (HCl) with 0.2 liter, 0.5 mol / dm 3 hydrochloric acid.
3.
Ethanol (C2H5OH) may be prepared by the fermentation of glucose (C6H12O6) of reaction formula: C6H12O6 2 → C2H5OH + 2 CO2
You want to make 1 kg of ethanol. How much glucose you need?
1. yes. because it's hot.
2. ~1.118 mol/dm^3
3. none, because the formula is wrong.
also, you must be 18 to post on this site.
>>123326
>Is the reaction when ethanol is burned in oxygen exothermic? Explain why / why not.
First balance the reaction of EtOH and O2
C2H6O + (3/2)O2 -> 2 CO2 + 3H2O
Then apply delta_H = [bonds broken - bonds formed].
Or, experimentally, measure the heat released on exhaustive combustion.
>What is the concentration of hydrochloric acid solution if you mixed 0.14 liters, 2 mol / dm 3 hydrochloric acid (HCl) with 0.2 liter, 0.5 mol / dm 3 hydrochloric acid.
I told you how to answer this on /sci/ already, but I did not bump.
>>123334
>C2H6O + (3)O2 -> 2 CO2 + 3H2O
well that's obviously not balanced
2C on each side
6H on each side
7H on each side
>>123335
I'm too drunk, I greentexed wrong, but this
>C2H6O + (3)O2 -> 2 CO2 + 3H2O
looks ok
1. exothermic due to the fact energy is released.
2. find moles of each, 2*0.14=0.28mols and 0.2*0.5=0.1mols add up the volumes and moles of HCl in solution, 0.14+0.2=0.34L and 0.28+0.1=0.38mols. concentration is just mols per litre so 0.38/0.34=1.12mols/L
3. need to find mols of ethanol, so mass divided by molar mass 1000/46.06=21.71mols. reaction is two to one (one glucose makes two ethanol) 21.71/2=10.85mols of glucose, then mass= moles times molar mass, 10.85*180.15=1955.6g=1.955kg
