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
The answer is B to prevent condensation from forming on the agar surface
Answer:
A
Explanation:
B and D have to do with plants
and C has nothing to do with cellular resporation.
Answer:
C
Explanation:
the rain does help the soli it can make bacteria