General Chemistry Answers

Calculate the boiling point of a solution made from 227 g of MgCl2 dissolved in 700. g of water. What is the boiling point of the solution? Kb = 0.512° C/m.

Calculate the freezing point of a solution made from 32.7 g of propane, C3H8, dissolved in 137.0 g of benzene, C6H6. The freezing point of benzene is 5.50°C and its Kf is 5.12°C/m.

Choose one chemical that humans add to water that is not present in lake water. Explain its purpose.

The Ministry of Natural Resources has sent you to sample two small lakes that are being considered sites for a fish farm. Below is the data you obtained during your sampling. Compare the sites and provide your recommendation for the best site. Provide your reasoning. 

SITE A

Nitrate - 5pm

Phosphate - 3ppm 

Dissolved O2 - 5.0ppm

pH - 6.8

SITE B

Nitrate - 1pm

Phosphate - 1ppm 

Dissolved O2 - 9ppm

pH - 8.0

you are asked to identify two clear, colourless beakers full of solution as acidic or basic. State what you would expect to see if beaker A was an acid and beaker B was a base for each of the following properties:

BEAKER A vs BEAKER B

- Conductivity

- pH

- Bromothymol blue

- Reaction with zinc

- Taste

Bacteria and viruses are inactivated by temperatures above 137 

∘

C

∘C in an autoclave. An autoclave contains steam at 1.00 atm

atm and 100 

∘

C

∘C.

At what pressure, in atmospheres, will the temperature of the steam in the autoclave reach 137 

∘

C

∘C, if n

n and V

V do not change?

1. YYouhave ice at 263 K (-10.0 oC) and 1.0 atm. What could you do to make the ice sublime?

2. A sample of dry ice (solid CO2) is cooled to 173 K (-100.0 oC), and is set on a table at room

temperature (298 K; 25 oC). At what temperature is the rate of sublimation and deposition the same (assume that

pressure is held constant at 1 atm)?

3. What are the significant differences between the phase diagrams of water and carbon dioxide? Discuss

each briefly.

Calculate the volume of hydrogen gas produced at STP when 30g of Zn is added to dilute hydrochloric acid at 33⁰c and 775mmHg pressure (H=1 , Zn=65 , cl =35.5) molar mass of gas at STP= 22.4 dm³

Given that 45.6 mL of a 0.453 M potassium iodide solution reacts with 0.355 M lead (ll) nitrate solution, what volume of lead (ll) nitrate is required for complete precipitation?

Pb(NO3) + 2 Kl —> Pbl2 + 2KNO3

What is the mass of dextrose that is in 45.6 g of a 10.3% solution of dextrose?