Answer:The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance (mol).
The molar mass of a compound can be calculated by adding the standard atomic masses (in g/mol) of the constituent atoms.
Explanation:
Answer : The molecular weight of this compound is 891.10 g/mol
Explanation : Given,
Mass of compound = 12.70 g
Mass of ethanol = 216.5 g
Formula used :

where,
= change in freezing point
= temperature of pure ethanol = 
= temperature of solution = 
= freezing point constant of ethanol = 
i = van't hoff factor = 1 (for non-electrolyte)
m = molality
Now put all the given values in this formula, we get


Therefore, the molecular weight of this compound is 891.10 g/mol
You have to use the equation q=mcΔT and solve for T(final).
T(final)=(q/mc)+T(initial)
q=the amount of energy absorbed or released (in this case 868J)
m=the mass of the sample (in this case 15.6g)
c= the specific heat capacity of the substance (in this case 2.41 J/g°C)
T(initial)=the initial temperature of the sample (in this case 21.5°C)
When you plug everything in, you should get 44.6°C.
Therefore the final temperature of ethanol is 44.6°C
I hope this helps. Let me know if anything is unclear.
Answer:because we are able to breath it in earth
Explanation: