Question

A) Problem Page

Four liquids are described in the table below. Use the second column of the table to explain the order of their freezing points, and the third column to explain the order of their boiling points.

For example, select '1' in the second column next to the liquid with the lowest freezing point. Select '2' in the second column next to the liquid with the next higher freezing point, and so on. In the third column, select '1' next to the liquid with the lowest boiling point, '2' next to the liquid with the next higher boiling point, and so on.

Note: the density of water is

/1.00gmL

.

solution freezing point boiling point 1.1 g of hydrobromic acid (HBr) dissolved in 250. mL of water (choose one)1(lowest)234(highest) (choose one)1(lowest)234(highest) 1.1 g of potassium nitrate (KNO3) dissolved in 250. mL of water (choose one)1(lowest)234(highest) (choose one)1(lowest)234(highest) 1.1 g of glycerin (C3H8O3) dissolved in 250. mL of water (choose one)1(lowest)234(highest) (choose one)1(lowest)234(highest) 250. mL of pure water (choose one)1(lowest)234(highest) (choose one)1(lowest)234(highest)

B)

A certain substance X has a normal freezing point of −9.2°C and a molal freezing point depression constant =Kf·3.45°C·kgmol−1.  Calculate the freezing point of a solution made of 17.g of urea

((NH2)2CO) dissolved in 150.g of X. Be sure your answer has the correct number of significant digits.

Answer 1