Methanol, CH_3OH, is sometimes used as an antifreeze for the water in automobile

Question

Methanol, CH_3OH, is sometimes used as an antifreeze for the water in automobile windshield washer fluids. How many grams of methanol must be added to 5.00 kg freezing point to -10.0degree C? For each mole of solute, the freezing point of 1 kg of water to lower 1.86degree C. 9) One test for vitamin C (ascorbic acid, C_6H_8O_6) is based on the reaction of the vitamin with iodine: C_6H_8O_6(aq) + I_2(aq) rightarrow C_6H_6O_6(aq) + 2H_(aq) a) If 25.0 mL of fruit juice requires 13.0 mL of 0.0100 M I_2 solution for reaction, what is the molarity of the ascorbic acid in the fruit juice? b) The Food and Drug Administration recommends that 60 mg of ascorbic acid be consumed per day. How many milliliters of the fruit juice in part (a) must a person drink to obtain the recommended dosage? 10 In many states, a person with a blood alcohol concentration of 0.080% (v/v) considered legally drunk. What volume of total alcohol does this concentration represent, assuming a blood volume of 5.0 L?

Explanation / Answer

Q8-

find mass of methanol required fo

m = 5 kg of water to lower

dTf = -10°C

so

Kf = -1.86 °C/m

m = molality

so....

dTf = -Kf*m

m = molality = mol of Solute / kg solvent

mol = mass/MW = mass of methanol / 32.04

substitute all values

-10 = -1.86*(mass) / (32.04*5)

mass = 10/1.86 * 5 * 32.04

mass of methanol required = 861.29 g in 5 kg of water

Please consider posting multiple questions in multiple set of Q&A. According to Chegg's Guidelines, we are only allowed to anwer to one question per set of Q&A

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---