Answer:
9.88
Explanation:
The higher the Ksp, the more soluble a compound is. Hence, Co(OH)₂ ranks as the least soluble hydroxide.
Its maximum concentration must be 1x10⁻⁶ M, and the reaction can be represented as:
Co(OH)₂(s) ⇄ Co⁺²(aq) + 2OH⁻(aq)
Thus, [Co⁺²] = 1x10⁻⁶M
Ksp = [Co⁺²] *[OH⁻]²
[[OH⁻]² = 5.9x10⁻¹⁵/1x10⁻⁶
[[OH⁻] = √(5.9x10⁻⁹)
[[OH⁻] = 7.6811x10⁻⁵
pOH = -log[OH⁻]
pOH = -log(7.6811x10⁻⁵)
pOH = 4.11
Knowing that pH + pOH = 14
pH = 14 - 4.11
pH = 9.88
The formula for Molarity is given by:
M = moles / V
To isolate V,
V = moles / M ------------------(1)
Moles can also be calculated as:
moles = mass / M.mass -------------(2)
Substituting the value of moles from equation 2 into equation 1 yields:
V = (mass / M.mass) / M
Plugging in the numbers gives:
V = (45 g / 164 g/mol) / 1.3 mol/dm³
V = 0.21 dm³.
The partial pressure of nitrogen gas is calculated to be 21.16 MPa.
The partial pressure of oxygen equates to 5.62 MPa, and the overall gas pressure is stated as 26.78 MPa.
This adheres to the principle that the total pressure in a gas system equals the sum of all individual gas partial pressures.
Thus, the total pressure in the system reflects the sum of the partial pressures of nitrogen and oxygen.
Accordingly, the partial pressure for nitrogen can be derived as follows: Total pressure minus the partial pressure of oxygen.
Thus resulting in: 26.78 - 5.62, which gives a partial pressure of nitrogen at 21.16 MPa.
Responses: a. 1.28 mol/L; b. 17.0 %; c. 0.0227; d. 1.29 mol/kg Explanation: a. Molar concentration: c = moles/litres. Moles = 167 × 1/159.61. After performing the calculation, Moles = 1.046 mol. Litres = 820 × 1/1000. Hence, Litres = 0.8200 L. Calculating the molar concentration gives c = 1.046/0.8200, resulting in c = 1.28 mol·L⁻¹. b. Percent by mass: Mass % = mass of solute / mass of solution × 100 %. Mass of solution = volume × density, therefore, Mass of solution = 820 × 1.195. By calculating this, Mass of solution = 979.9 g. Thus, Mass % = 167/979.9 × 100, which results in Mass % = 17.0 %. c. Mole fraction: χ = moles of solute / (moles of solvent + moles of solute). Mass of solvent = mass of solution – mass of solute; namely, Mass of solvent = 979.9 – 167. Converting this to moles gives Moles of water = 812.9 × 1/18.02, which results in Moles of water = 45.11 mol. The total moles are 1.046 + 45.11, leading to Total moles = 46.16 mol. Finally, the mole fraction is calculated as χ = 1.046/46.16, equating to χ = 0.0227. d. Molal concentration: b = moles of solute / kilograms of solvent. Mass of solvent = 812.9 g = 0.8129 kg. Therefore, the molal concentration yields: b = 1.046/0.8129 = 1.29 mol/kg.
