Bihar Board Class 12 (Science) Solutions — practice questions
112 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice Bihar Board 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:Which description correctly defines a solution in chemistry?Which component of a solution determines the physical state in which the solution exists?A solution of hydrogen in palladium belongs to which solute-in-solvent type?German silver is a mixture of which metals?Fluoride ions in drinking water at about which level cause teeth to become mottled?A solution labelled 10% glucose in water by mass is made from what?A solute present only in trace amounts is most conveniently expressed in which unit?31% ethylene glycol (62 g/mol) by mass in water: mole fraction of glycol?How is the molarity of a solution defined?Which of these concentration terms changes with temperature?Find the molality of a solution of 6.0 g of urea (60 g/mol) dissolved in 250 g of water.Naphthalene dissolves readily in which of these solvents?No more solute dissolves at this temperature. What is the solution called?If dissolving a solid in a nearly saturated solution is endothermic, raising temperature does what to solubiliWhy does pressure barely change the solubility of solids in liquids?At constant temperature, Henry's law links the solubility of a gas in a liquid to which quantity?At a given pressure, a gas with a larger Henry's law constant KH has what solubility?Why do aquatic species prefer cold water to warm water?Soda bottles are sealed under high pressure to do what?The painful condition called bends in scuba divers is caused by bubbles of which gas in blood?Weakness and confused thinking in climbers caused by low blood oxygen at high altitude is called what?Gas solubility in a liquid falls as temperature rises because gas dissolution is what?A gas has KH = 50 kbar in water. What mole fraction of it dissolves at a partial pressure of 1 bar?A gas has KH = 100 kbar in water. About how many millimoles dissolve in 1 L of water (55.5 mol) at 1 bar partiBy Raoult's law, partial vapour pressure is proportional to which quantity?For an ideal binary solution, how does total vapour pressure vary with the mole fraction of one component?The vapour above an ideal mixture is richer in which component?Pure A and B have vapour pressures 200 and 400 mm Hg. Ideal total at xB = 0.5?Pure A: 300, pure B: 600 mm Hg; ideal liquid xB = 0.25. What is yB in the vapour?Pure A: 450, B: 700 mm Hg. An ideal mix totals 600 mm Hg. What is xA?Why does a non-volatile solute lower vapour pressure?Adding 1.0 mol of sucrose to 1 kg of water lowers its vapour pressure about as much as adding which solute?Which pair of liquids forms a nearly ideal solution?Positive deviation means A-B forces, versus A-A and B-B, are what?Why do ethanol and acetone show positive deviation?Why does a chloroform and acetone mixture show negative deviation?What is an azeotrope?Fractional distillation of a fermented ethanol and water mixture stops at roughly what ethanol content by voluNitric acid and water form a maximum boiling azeotrope at about what HNO3 mass percentage?Maximum boiling azeotropes come from which deviation?Colligative properties of a dilute solution depend mainly on what?Relative lowering of vapour pressure equals what?Pure water is at 30 mm Hg. What is p with a non-volatile solute at x = 0.02?6.0 g urea (60 g/mol) in 90 g water; pure water p = 25.0 mm Hg. Solution p?36 g glucose (180 g/mol) in 500 g water (Kb 0.52). Boiling point rise?2.0 g solute in 100 g benzene (Kb 2.53) raises bp by 0.506 K. Molar mass?At the freezing point, which holds for solid and liquid phases?62 g ethylene glycol (62 g/mol) in 500 g water, Kf = 1.86. Freezing point?In osmosis, which way does solvent flow across the membrane?Which of these is a synthetic semipermeable membrane?Osmotic pressure is the excess pressure that must be applied to which side to stop osmosis?For dilute solutions, osmotic pressure is directly proportional to which concentration term?What is the osmotic pressure of a 0.10 M glucose solution at 300 K? (R = 0.083 L bar/mol K)1.0 g protein in 100 mL gives 2.49 × 10^-3 bar at 300 K (R 0.083). Molar mass?Normal saline, isotonic with the fluid inside blood cells, contains what mass/volume percentage of NaCl?Blood cells placed in NaCl solution stronger than 0.9% (mass/volume) will do what?A salt solution in which blood cells swell because water flows into them is called what?Why does a raw mango shrivel in strong brine?Reverse osmosis is used chiefly for which practical purpose?What does the van't Hoff factor i account for?If a solute dissociates, its measured molar mass is what?Ethanoic acid dimerises almost completely in benzene. What is its approximate van't Hoff factor?Solute molecules such as acid dimers associate in which solvents?For a solute that associates in solution, the van't Hoff factor i is what?What is the van't Hoff factor of K2SO4 on complete dissociation?Ideally, how much does 1 mol KCl in 1 kg water raise the boiling point? (Kb 0.52)Assuming complete dissociation, what is the freezing point depression of 0.10 m aqueous NaCl? (Kf = 1.86 K kg/Benzoic acid forms dimers in benzene and shows a van't Hoff factor of 0.6. What percentage of the acid is assoAt fixed concentration, osmotic pressure varies how with absolute temperature?For a fixed mass of solute, how do colligative effects vary with molar mass?Brass is a solid solution of which metals?Plotting a gas's partial pressure against its mole fraction gives what slope?For dilute solutions, elevation of boiling point is directly proportional to which quantity?Osmotic pressure in Pa of 1.0 g polymer (M = 185,000) in 450 mL at 37 C?What mass of ascorbic acid (176 g/mol) in 75 g of acetic acid lowers its melting point by 1.5 C? (Kf = 3.9 K k22 g of benzene is dissolved in 122 g of carbon tetrachloride. What is the mass percentage of benzene?30% benzene (78 g/mol) by mass in CCl4 (154 g/mol). Mole fraction of benzene?H2S has a solubility of 0.195 m in water at STP (0.987 bar). Taking 55.5 mol water per kg, what is its Henry'sSea water (1030 g per litre) holds 6 × 10^-3 g O2 per litre. What is this in ppm?The van't Hoff factor equals the normal molar mass divided by what?Why does a non-volatile solute raise the boiling point?A binary solution behaves ideally when A-B attractive forces, compared with A-A and B-B forces, are how?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?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?Molality is defined as moles of solute per what quantity?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?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?