Answer: 72.41% and 26.90% respectively.
Explanation:
At 60°C, you can dissolve 46.4g of acetanilide in 100mL of ethanol. If you lower the temperature, at 0°C, you can dissolve just 12.8g, which means (46.4g-12.8g)=33.6g of acetanilide must have precipitated from the solution.
We can calculate recovery as:

So the answer to the first question is 72.41%.
For the second part just use the same formula, the mass of the precipitate is the final mass minus the initial mass, (171mg-125mg)=46mg.

So the answer to the second question is 26.90%.
C becuase that is the one that you would have to do becuase that is the only option
Mass / volume = density
30.943g / 35ml = 0.88408571g/ml
Answer:
The most recent ice age ended about 10,000 years ago
Explanation:
The last ice age began 110,000 years ago and ended 10,000 years ago, leading to the temperature of the Earth, expansions of glaciers and polar ice caps were made.