ppm = (mass of solute/mass of solution) x 10⁶
Mass of solute = 0.025 g
Mass of solution = 0.025 + 100 = 100.025 g
Concentration in ppm = (0.025/100.025) x 10⁶ = 250 ppm.

Given,
Initial concentration, M₁ = 2 M
Initial total volume, V₁ = 15 ml
Final total volume, V₂ = 15 + 285 = 300 ml
Final concentration, M₂ = to be found
Before and after adding water number of moles of solute remain constant since it does not react with water.
Number of moles = concentration x volume
Thus, M₁ x V₁ = M₂ x V₂
On substituting, M₂ = (2 x 15)/300 = 0.1 M.

Alloys of mercury with or metals are called amalgams. An alloy is a type of solid solution (solid in solid). Some important amalgams are zinc amalgam, potassium amalgam, sodium amalgam, aluminium amalgam, and tin amalgam.

Saturated solutions are those which contain maximum amount of solute that is soluble and cannot be furr dissolved. Dilute solutions have a very low concentration of salt. Unsaturated solutions have concentration of solute lesser than its solubility. Supersaturated solutions contain more amount of solute than how much is soluble in solvent. In or words, adding more solute to a saturated solution results in a supersaturated solution.

Given,
k_f = -3.83 k kg mol^-1
Mass of solute, w₂ = 228 g
Mass of solvent, w₁ = 500 g
Molar mass of solute, M₂ = 76 g/mole
Moles of solute = w₂/M₂ = 228/76 = 3 moles
Molality of solution, m = Number of moles of solute/mass of solvent (kg)
m = 3 moles/0.5 kg = 6 molal
We know, ΔT_f = k_f x m
ΔT_f = -3.83 x 6 = -23°C.

°R represents temperature measured on Rankine scale. Typically, boiling point of water is measured as 100 °C on Celsius scale. The conversion of Celsius to Rankine scale is R = C x 9/5 + 491.67.
Considering boiling point of water as 100 °C, R = 100 x 9/5 + 491.67 = 671.67 °R
°F, °r represent Fahrenheit and Reaumur scale, respectively.

The Van?t Hoff Factor (i) is equal to ratio between normal molar mass of solute and its abnormal mass. The glucose molecules neir associate nor dissociate. Hence, abnormal mass is equal to normal molar mass of solute and Van?t Hoff factor is equal to 1.

Henry?s law states that partial pressure of a gas in vapor phase varies directly with its mole fraction in solution. At higher altitudes partial pressure of O₂ decreases hence decrease in its concentration which causes difficulty in breathing.

Given,
Degree of association (α) = 50% = 0.5
Number of molecules associated (n) = 2
Let Van?t Hoff factor = i
We know that for solutes that associate in solution, i = 1 + ((1/n) -1) x α
= 1 + ((1/2) ? 1) x 0.5
= 1 – (0.5 x 0.5)
= 0.75
Therefore, Van?t Hoff factor is equal to 0.75.

Given,
Observed pressure = 76 torr
According to Raoult?s law,
p_A = x_A x p_A⁰ = 5/15 x 64 = 21.33 torr
p_B = x_B x p_B⁰ = 10/15 x 76 = 50.67 torr
Therefore, pressure expected by Raoult?s law = 21.33 + 50.67 = 72 torr.
Thus, observed pressure (70 torr) is less than expected value. Hence, solution shows negative deviation.