Answer:
NH3
Explanation:
Which salt is least soluble at 90 degrees Celsius
In my opinion I believe it would be motion because depending on how fast the person is going it would determine the outcome of the race
Answer:
B) 0.025 
Explanation:
Solution of the problem is in picture attached,
We will use boiling point formula:
ΔT = i Kb m
when ΔT is the temperature change from the pure solvent's boiling point to the boiling point of the solution = 77.85 °C - 76.5 °C = 1.35
and Kb is the boiling point constant =5.03
and m = molality
i = vant's Hoff factor
so by substitution, we can get the molality:
1.35 = 1 * 5.03 * m
∴ m = 0.27
when molality = moles / mass Kg
0.27 = moles / 0.015Kg
∴ moles = 0.00405 moles
∴ The molar mass = mass / moles
= 2 g / 0.00405 moles
= 493.8 g /mol