Search questions
Use text search or combine filters to find exactly the questions you need.
Class 12 · Chemistry
→The normal molar mass of a solute is 90 g mol⁻¹. If its observed molar mass obtained from a colligative-property measurement is 60 g mol⁻¹, what is the van’t Hoff factor?
Class 12 · Chemistry
→A 500 mL solution is prepared using 0.75 g of an unknown solute. Its osmotic pressure at 300 K is 0.123 atm. If R = 0.082 L atm K⁻¹ mol⁻¹, what is the molar mass?
Class 12 · Chemistry
→A 3.6 g sample of a substance dissolved in 250 g of solvent produces a boiling-point elevation of 0.156 K. If Kb = 0.52 K kg mol⁻¹, what is the molar mass of the substance?
Class 12 · Chemistry
→When 2.4 g of a nonelectrolyte is dissolved in 300 g of water, the depression in freezing point is 0.1488 K. If Kf = 1.86 K kg mol⁻¹, what is the molar mass of the solute?
Class 12 · Chemistry
→Why is the osmotic-pressure method considered more reliable for determining the molar mass of large molecules?
Class 12 · Chemistry
→If the osmotic-pressure method gives a molarity of 0.015 mol L⁻¹ and 400 mL of the solution contains 1.2 g of solute, what is the molar mass of the solute?
Class 12 · Chemistry
→When \(10\,g\) of an unknown solute is dissolved in \(1\,kg\) of solvent, the freezing-point depression is \(\Delta T_f=0.093\,K\). If \(K_f=1.86\,K\,kg\,mol^{-1}\), what is the molar mass of the solute? Assume no association or dissociation.
Class 12 · Chemistry
→A solute has an observed molar mass of \(72\,g\,mol^{-1}\). If its van’t Hoff factor is \(i=1.5\), what is its true molar mass?
Class 12 · Chemistry
→When \(5\,g\) of solute is dissolved in \(500\,g\) of solvent, the boiling-point elevation is \(\Delta T_b=0.052\,K\). If \(K_b=0.52\,K\,kg\,mol^{-1}\) and \(i=0.5\), what is the true molar mass?
Class 12 · Chemistry
→An \(AB\)-type solute is 25% dissociated. If its observed molar mass is \(80\,g\,mol^{-1}\), what is its true molar mass?
Class 12 · Chemistry
→A substance forms dimers to the extent of 40%. If its true molar mass is \(90\,g\,mol^{-1}\), what is its approximate observed molar mass?
Class 12 · Chemistry
→An \(AB_2\) solute has a true molar mass of \(150\,g\,mol^{-1}\). If it is dissociated to the extent of 50%, what is its observed molar mass?
Class 12 · Chemistry
→If \(1.6\,g\) of solute dissolved in \(200\,g\) of water produces a freezing-point depression of \(\Delta T_f=0.372\,K\), and \(i=2\), what is the true molar mass? Take \(K_f=1.86\,K\,kg\,mol^{-1}\).
Class 12 · Chemistry
→A \(250\,mL\) solution is prepared using \(2.5\,g\) of solute. At \(300\,K\), its osmotic pressure is \(\pi=1.23\,atm\). If \(i=2\), what is the true molar mass? Use \(R=0.082\,L\,atm\,K^{-1}\,mol^{-1}\).
Class 12 · Chemistry
→A solute has a van’t Hoff factor of \(i=0.75\) and an observed molar mass of \(160\,g\,mol^{-1}\). What is its true molar mass?
Class 12 · Chemistry
→A solute has a van’t Hoff factor of \(i=1.25\) and an observed molar mass of \(80\,g\,mol^{-1}\). What is its true molar mass?
Class 12 · Chemistry
→The observed molar mass of an AB₃ solute is 4/7 of its true molar mass. What is the degree of dissociation of the solute?
Class 12 · Chemistry
→The relative lowering of vapour pressure is 0.05. If 1 g of solute is dissolved in 18 g of water, what is the approximate molar mass of the solute?
Class 12 · Chemistry
→In a vapour-pressure method, the mole fraction of the solute is x₂ = 0.02. If 0.18 g of solute is dissolved in 9 g of water, what is the approximate molar mass of the solute?
Class 12 · Chemistry
→