Question

PLEASE HELP!!

1. A student collected the following data for a fixed volume of gas: Temperature (⁰C) Pressure (mm of Hg) 10 726 20 750 40 800 70 880 100 960 150 ??? Fill in the missing data point. Show all calculations leading to an answer.
2. You are given a clear solution of KNO3. Using 3 – 4 sentences (in your own words) explain how you would determine if the solution is unsaturated, saturated or supersaturated.
3. Explain why gasoline will not dissolve in water.

Answer 1

1. p = 1090 mmHg

2. and 3. See below.

Step-by-step explanation:

1) Pressure-Temperature relationship

a) Sketch the p-T graph.

The graph is linear (see below).

b) Calculate the slope of the line

m = (y₂ - y₁)/(x₂ - x₁)

m = (960 – 726)/(100 – 10)

m = 234/90

m = 2.60 mmHg/°C

c) Extrapolate the line to 150 °C

Start from (100, 960).

2.60 = (y₂ - 960)/(150 - 100)

2.60 = (y₂ - 960)/50 Multiply each side by 50

130 = y₂ - 960 Add 960 to each side

y₂ = 1090 mmHg

2) Concentration of solutions

Add a small crystal of KNO₃ to the solution.

• If the crystal dissolves, the solution is unsaturated.
• If the crystal neither grows nor shrinks, the solution is saturated.
• If a large amount of crystals forms, the solution is supersaturated.

3) Solubility of gasoline in water.

Water molecules are highly polar, with strong attractive forces to each other.

Gasoline molecules are nonpolar hydrocarbons, with weak attractions to each other and to water molecules.

The water molecules are so strongly attracted to each other that the gasoline cannot mix with them, so the liquids form two separate layers