The normal freezing point of a certain liquid

X

is

0.4°C

, but when

5.90g

of urea

NH22CO

are dissolved in

450.g

of

X

, it is found that the solution freezes at

−0.5°C

instead. Use this information to calculate the molal freezing point depression constant

Kf

of

X

.
Be sure your answer has the correct number of significant digits.

Assume that the variables x and y are inversely related. if k = 18, what is the value of y for each of the following points? be sure and record your data to be used in the following problem.

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

Which answer tells the reason the earth’s climate is getting warmer? too many animals are becoming extinct. large glaciers are melting in antarctica. the earth is moving closer to the sun. driving cars gives off gases that trap heat in the atmosphere.