Question

Justify the following with clear hand writing and details: I'll be thankful.

- What is the mole fraction of HCl in a 36% by weight aqueous solution of HCl?

- A solution contains 4.00 g NaOH, 5.61 g KOH, and 1.03 g RbOH in 90.0 g of water. The solution’s density is 1.08 g/mL. What is the molality of OH– ?

- Why does a can of soda fizz when it is opened?

- Adding NaCl to water results in a solution with greater electrical conductivity than pure water.

a. If you add NaCl to oil, do you expect the electrical conductivity of the oil to increase? Why or why not?

b. Is solid NaCl a good conductor of electricity? Why or why not?

Answer 1

36% by weight aqueous solution of HCl have 36 gm HCl and 64 gm of water

36 gm HCl = 36/36.46 = 0.9873 Moles

64 gm of water = 64 / 18 = 3.555 Moles

Mole  fraction of HCl = 0.9873 / 0.9873 + 3.55 = 0.217

Question 2

4.00 g NaOH = 4 / 40 = 0.1 Moles

5.61 g KOH = 5.61 / 56.1 = 0.1 Moles

1.03 gm RbOH = 1.03/102.47 = 0.01 Moles

Mass of the solvent = 90 * 1.08 = 97.2

Molality of the solution = 0.1 + 0.1 +0.01 / 0.0972 = 2.16 m

Question 3

An unopened soda can is virtually bubble-free because the pressure inside the cankeeps the carbon dioxide dissolved in the liquid. When you crack open the can, you release the pressure and allow the gas bubbles to wiggle free from the liquid and rise to the surface

Question 4

Adding NaCl to water results ionization which can dissociate to Na+ and Cl- ions. But adding NaCl to oil no dissociation will occur. Hence it will increase the electrical conductivity of the oil