Question

earchSelect 559 your on the 8.) Dipole and its geome. determine that t. Laboratory Experiments 113 QUESTIONS 1. Does the solubility of the oxalic acid solute increase or decrease with temperature? Increases with temperature. 2. Is there a simple relationship that governs the temperature dependence of the solubility of compounds in aqueous solutions? Depends on UC entho ply Chano o decide which there Kinetic energy can spread throuo, hout the IN the custom When lower sold disse ante into the volume of the sofuton, cartofna thermal energy with 3. Write an equation for the solubility equilibrium for oxalic acid dihydrate and include heat on the reactant or product side. 4. A saturated solution contains 6.51 g Na2SO4 in 33.30 mL of water at 16.0 °C. Determine the solubility in g solute/100 g H20. Determine the mole fraction of solute at 16.0 °C.

Answer 1

Answer 3

Solubility equilibrium of oxalic acid dihydrate (H₂C₂O₄.2H₂O)

H₂C₂O₄.2H₂O (s) + Heat <------> C₂O₄^2- (aq) + 2H⁺ (aq) + 2H₂O (l)

Answer 4

Density of water = 1.00 g/mL

Mass of 33.30 mL of water = 33.30g

Mass of Na₂SO₄ in 33.30 g of water = 6.51 g

Mass of Na₂SO₄ in 100 g of water

= (6.51 g*100 g/33.30 g)

= 19.5 g

Solubility = 19.5 g/100 g of water.

Molar mass of solute, Na₂SO₄ = 142.04 g/mol

Moles of solute = 19.5 g/142.04 g/mol = 0.137 mol

Moles of water = 100 g/18 g/mol = 5.56 mol

Total moles = 0.137 + 5.56 = 5.70

Mole fraction of solute = 0.137/5.70 = 0.024