As you increase elevation the atmospheric pressure decreases, which means the bo

Question

As you increase elevation the atmospheric pressure decreases, which means the boiling point of water also decreases. In Denver, the Mile High City, the boiling point of water is 95.0 degree C. a. How many grams of your assigned salt (using the van't Hoff factor you calculated in lab) would need to be added to 1.0 gallon (3.8 kg) of water to raise the temperature to 100.0 degree C, the boiling point of water at sea level. b. In the USA, a volume (cup) is used more commonly in cooking than a weight (grams). Convert the grams of salt you calculated into cups (1 cup = 273 g). c. Ignoring the potential toxicity of your assigned salt, is the amount of salt needed to increase the boiling point of the water 5 degree C reasonable? Explain. Record the results from a group with a different unknown below.

Explanation / Answer

2. colligative property

a. let the salt in question is NaCl

to raise temperature of water from 95 to 100 oC

dTb = 100-95 = 5 oC

use,

dTb = iKbm = 5 oC

       = 2 x 0.512 x grams NaCl/58.44 x 3.8

grams of NaCl salt needed = 1084.33 g

b. with,

1 cup = 273 g

thus,

amount of salt NaCl = 1084.33 g/273 = 3.97 cups (or 4 cups)

c. Yes, to raise the temperature of water by 5 oC the amount of salt needed for 3.8 kg water is reasonable.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.