CBSE Class 12 (Science) Solutions — practice questions
81 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 12 (Science) Solutions in the app →The mole fraction of urea ($M = 60\,\text{g/mol}$) in an aqueous solution containing $6\,\text{g}$ of urea in For an ideal solution containing two volatile liquids A and B, Raoult's law gives the total vapour pressure asOsmotic pressure of a dilute solution is expressed by van't Hoff's equation as:Two solutions are said to be **isotonic** if they:If $\mathrm{NaCl}$ undergoes complete dissociation in water, the van't Hoff factor $i$ is:Desalination of sea water is best carried out by:The MOLARITY of a solution containing 58.5 g NaCl dissolved in 1 L of solution is:HENRY'S LAW states that at constant temperature:A MINIMUM-BOILING azeotrope arises from:Which of these is NOT a colligative property?Salt is sprinkled on icy roads in cold countries to:The van't Hoff factor (i) for sodium chloride (NaCl) in water is approximately:A solution is best described as which kind of mixture?In a binary solution, which component is called the solvent?What does the solvent determine about a solution?A mixture of oxygen and nitrogen gases is a solution of which type?An amalgam of mercury with sodium is an example of which solute-solvent pair?Hydrogen absorbed in palladium is a solution of which kind?Camphor vapour dispersed in nitrogen gas is a solution of which type?A solution of 10% glucose in water by mass contains how much water per 100 g of solution?Commercial bleaching solution contains what mass percentage of sodium hypochlorite?A 35% (v/v) ethylene glycol antifreeze lowers the freezing point of water to about what value?Which concentration unit is commonly used in medicine and pharmacy?Which unit is convenient when a solute is present only in trace quantities?Parts per million is the number of parts of a component multiplied by what factor, per total parts?In any solution, the mole fractions of all the components add up to what value?What is the molarity of a solution of 5 g NaOH (40 g/mol) in 450 mL of solution?Molality is defined as moles of solute per what quantity?2.5 g of ethanoic acid (60 g/mol) is dissolved in 75 g of benzene. What is the molality?Which of these concentration measures changes with temperature?A 1.00 m aqueous KCl solution has how many grams of KCl (74.5 g/mol) per kg of water?What is the solubility of a substance?Which rule explains why naphthalene dissolves in benzene but not in water?Which solute dissolves readily in water but not in benzene?A solution that is in dynamic equilibrium with undissolved solute is called what?If dissolving a solid in a liquid is endothermic, how does a rise in temperature affect its solubility?If dissolution of a solid is exothermic, what happens to its solubility on heating?In p = KH x, what does x represent?At a given pressure, a gas with a higher KH value has what solubility in the liquid?Why is a soda water bottle sealed under high pressure?Nitrogen at 0.987 bar is bubbled through water at 293 K with KH of 76,480 bar. What is its mole fraction in soAt 0.987 bar and 293 K (KH = 76.48 kbar), how many millimoles of N2 dissolve in 1 L of water?The total vapour pressure over a solution of two volatile liquids is found using which law?For an ideal binary mixture, how does ptotal vary with the mole fraction x2 of component 2?At equilibrium, the vapour above an ideal liquid mixture is richer in which component?Pure CHCl3 and CH2Cl2 have vapour pressures 200 and 415 mm Hg at 298 K. For x(CH2Cl2) = 0.688, what is ptotal?For an ideal solution, what are the values of enthalpy and volume of mixing?Ideal solutions form when A-A and B-B forces are about equal to which forces?In a solution showing positive deviation from Raoult's law, how do A-B interactions compare with A-A and B-B?Which mixture shows positive deviation from Raoult's law?What is an azeotrope?Which pair forms a maximum boiling azeotrope?Fractional distillation of ethanol-water from fermentation gives about what ethanol content by volume?The nitric acid-water azeotrope boils at what temperature?Colligative properties depend on which feature of a solution?The relative lowering of vapour pressure equals which quantity?A solid of 0.5 g in 39.0 g benzene (78 g/mol) lowers vapour pressure from 0.850 to 0.845 bar. What is its molaA liquid boils at the temperature where its vapour pressure equals what?Why does pure water boil at 373.15 K at 1 atm?For dilute solutions, elevation of boiling point is proportional to what?What is the unit of the molal elevation constant Kb?Kb and Kf depend primarily on which factor?What property must a semipermeable membrane have?What concentration of sodium chloride is the normal saline that is isotonic with blood cells?Edema, or puffiness from eating too much salt, is caused by what process?Why does a raw mango shrivel when placed in strong brine?Reverse osmosis occurs when a pressure larger than what is applied to the solution?Reverse osmosis is used for desalination of sea water with which kind of membrane?When a solute dissociates into ions, how does the experimental molar mass compare with the true value?Why does ethanoic acid in benzene show a molar mass about twice the normal value?The van't Hoff factor i is the ratio of observed to calculated what?In association of solute molecules, what is the value of i?The van't Hoff factor for ethanoic acid in benzene is nearly what?What is the approximate van't Hoff factor for dilute aqueous KCl?How is the van't Hoff factor used in the freezing point depression formula?The van't Hoff factor of K2SO4 at high dilution approaches what number?A sample of 22 g benzene is dissolved in 122 g of CCl4. What is the mass percentage of benzene?A 30% by mass benzene (78 g/mol) in CCl4 (154 g/mol) solution has what mole fraction of benzene?30 mL of 0.5 M H2SO4 is diluted to 500 mL. What is the new molarity?Liquids A and B have pure vapour pressures 450 and 700 mm Hg at 350 K. What is x(A) if ptotal is 600 mm Hg?About how much sucrose (342 g/mol) must be added to 500 g water to raise its boiling point by 0.37 K (Kb = 0.5