Answer:
How can I tell if a chemical reaction is occurring? A chemical reaction is usually accompanied by easily observed physical effects, such as the emission of heat and light, the formation of a precipitate, the evolution of gas, or a color change.
Explanation:
Molality= mol/ Kg
if we assume that we have 1 kg of water, we have 3.19 moles of solute.
the formula for mole fraction --> mole fraction= mol of solule/ mol of solution
1) if we have 1 kg of water which is same as 1000 grams of water.
2) we need to convert grams to moles using the molar mass of water
molar mass of H₂O= (2 x 1.01) + 16.0 = 18.02 g/mol
1000 g (1 mol/ 18.02 grams)= 55.5 mol
3) mole of solution= 55.5 moles + 3.19 moles= 58.7 moles of solution
4) mole fraction= 3.19 / 58.7= 0.0543
We need to first add both of the solution volumes together 35+115=150. Now we can divide the volume of the ethanol by the total volume 35/150=.233. To double check we can multiply the total volume by the percentage of ethanol by volume we got as a solution 150x.233=35. So the percentage by volume of ethanol in the solution is .233x100=23.3%.