Question

The answers for part a-c are on there. Just have no idea how to do the work.

Ans: a) 7,000 ng/L: b) 7.2 10-mol/L; c) 72,000 PM 3. Sulfur dioxide, SO2(g), is a colorless gas at ambient temperature and pressure. It has a pungent. irritating odor with an odor threshold of approximately 2.5 ppmv. a) Express that odor threshold in units of mol of sulfur dioxide per cubic meter of air at 1 atm of total pressure and 25 °C. b) Express the odor threshold in units of mg/mat 1 atm of total pressure and 25 °C. -C) Express the odor threshold in units of partial pressure of sulfur dioxide at 1 atm of total pressure and 15 °C. d) At the elevation of Denver, CO, atmospheric pressure is about 0.82 atm. Express the sulfur dioxide standard in units of mg/m3 at 0.82 atm and a temperature of 5 °C. Ans: a) 1.0 x10 mol/m3; b) 6.5 mg/m'; c) 2.5 x10-atm

Answer 1

Samples of gaseous mixtures are frequently calculated in terms of ppmv. Here, ppmv stands for parts per million by volume. It means in this case, by volume SO₂ has 2.5 parts out of 10⁶ parts of air. When we know the ppmv value of SO₂ gas, we can easily convert it into moles and mg/m³ by rearranging ideal gas equation i.e. PV=nRT and Avagadro's gas law i.e all ideal gases at 1 mole occupies 22.4 l of volume at STP.

DATE Q- (a) - Density Tag/m3) Ppmv x molar mass x 1000 4.465T ( . = 2.5 X 10-6 x 6 4.066 X 1000 24.465 x 10 3 160.165 24.465 - a 6-5467 x 10-8 g / m3 - ① Density I and = mass. volume no. of neoles & mass molae neess no. of neoles . - Density x volume molee mass = 6.5467X1086/m3) x 1 (m3) 64.066 ) ? 0.1021 *10-3 z 1.0218 10-4 (6) Densile & 6.5467x 10 g/m² from @ 26.5467 X 10 3 x 10vo ny/m3 6.5467 mg/m²