ASSIGNMENT

Show your work clearly enough to enable the marker to understand what you are doing. Marks will be deducted for omitting units and the incorrect use of significant figures.

1. A water sample collected from the Gaspereau River has a pH of 6.54. Calculate the concentration of H₃O⁺.

2. A drinking water sample collected from Elliott Hall has [H₃O⁺]= 8.5 x 10^-5 mol/L. Calculate the pH.

3. 123 mL of a 1.1 mol/L glucose solution is diluted to 500.0 mL. Calculate the molarity of the diluted solution.

4. An ibuprofen suspension for infants contains 100 mg/5.0 mL suspension. The recommended dose is 10 mg/kg body weight. How many millilitres of this suspension should be given to an infant weighing 7.9 kg?

5. The composition of the Earth's atmosphere is given below:

Component     Concentration
N₂                  78.09% (v/v)
O₂                  20.95% (v/v)
CO₂                400. ppm_v

Calculate the partial pressure of O₂ and CO₂ in bar. (Hint: use Dalton's law to calculate the partial pressures)

6. The average area of land burned by forest fires every year in Canada is 2.5 million hm² (square hectometres or hectares). Calculate the area in square kilometres.

7. The Toyota Prius, a hybrid electric vehicle, has a combined consumption rating of 3.811100 km in the city. How many kilometres can the Prius travel on 18 L of gasoline.

8. A bottle of concentrated aqueous sulfuric acid has a concentration of 18.0 M.

a) How many millilitres of reagent should be diluted to 1.000 L to prepare a 1.00 M solution of sulfuric acid?
b) If concentrated sulfuric acid is 98.0 wt%, calculate the density.

9. Calculate the volume of 6.0 mol/L sulfuric acid required to produce 25.0 g of H₂(g) according to the reaction shown below.
2A1(s) + 3H₂SO₄(ag) → Al₂(5O₄)₃(aq) + 3H₂(g)

10. A student analyzed a sample of chloride by precipitation the chloride as silver chloride.

A 1.000-g sample gave 0.6000 g of silver chloride. Calculate the wt% of chloride in the sample.

11. A student analyzed a sample of soda ash weighing 0.4240 g by titration with 0.1000 M hydrochloric acid.

a) Calculate the wt% of Na₂CO₃ in the soda ash.
b) If the certified concentration of in the soda ash is 50.00 wt%, calculate the percent error.

12. Dust falls on Halifax at a rate of 65 mg m^-2 day^-1. Major metallic elements in the dust include Al, Mg, Cu, Zn, Mn, and Pb. Pb accumulates at a rate of 0.03 mg m^-2 day^-1. How many metric tons of Pb fall on the 535 km of Halifax in 1 year.

13. 1.6 ppm fluoride is recommended for the prevention of tooth decay. Consider a reservoir with a diameter of 450. M and a depth of 10.0 m. How many grams of sodium fluoride should be added to give 1.6 ppm?

14. Calculate the following using the Real Rule for Sig Figs.

a) [3.1(±0.3) - 1.4 (±0.1)] / 8.5(±0.6) =
b) 9.2 (±0.7) x [5.4(±0.3) 10^-3+ 5.6(±0.1) x 10^-3]=
c) [8.47(±0.05)]^1/3 =
d) log [8.47(±0.05)] =