Answer:
A). It encouraged them to rely on observation and experimentation to support their conclusions.
Explanation:
Answer : The molar mass of unknown compound is 152.38 g/mole
Explanation :
Depression in freezing point = 
Mass of unknown compound = 16.5 g
Mass of water = 106.0 g
Formula used :

where,
= depression in freezing point
i = Van't Hoff factor = 1 (for non-electrolyte)
= freezing point constant for water = 
m = molality
Now put all the given values in this formula, we get


Therefore, the molar mass of unknown compound is 152.38 g/mole
Answer: Molarity of the unknown calcium hydroxide solution is 0.217 M.
Explanation:
Given:
= 50.00 mL,
= ?
= 43.43 mL,
= 0.250 M
Formula used is as follows.

Substitute the values into above formula as follows.

Thus, we can conclude that molarity of the unknown calcium hydroxide solution is 0.217 M.