Recent questions tagged ch2

A 5% solution (wt/volume) of cane sugar is isotonic with 0.877% (wt/volume) of urea solution.Find the molecular weight of urea,if molecular weight of sugar is 342.

asked Aug 6, 2014 by sreemathi.v

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The Henry's law constant for oxygen dissolved in water is $4.34\times 10^4$ atm at $25^{\large\circ}$C.If the partial pressure of oxygen in air is 0.2atm,under atmospheric conditions,calculate the concentration (in moles per litre) of dissolve oxygen in water in equilibrium with air at $25^{\large\circ}$C.

asked Aug 6, 2014 by sreemathi.v

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The solubility of oxygen in water is $2.43\times 10^{-3}$ mole/litre at $25^{\large\circ}$C and 1.0atm pressure.Calculate the concentration of oxygen at $25^{\large\circ}$C and 0.2atm pressure.

asked Aug 6, 2014 by sreemathi.v

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Calculate the molarity of water if its density is $1000g/m^3$

asked Aug 6, 2014 by sreemathi.v

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A sample of sulphuric acid is 98% $H_2SO_4$ by weight (density =$1.10gmL^{-1})$.Calculate normality

asked Aug 6, 2014 by sreemathi.v

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If the freezing point depression constant of a solvent is $20.0\;K\;kg\;mol^{-1}$. If its $\Delta_{fus} H^0_m=2.74\;kJ\;mol^{-1}$ and its molar mass is $84.2\;g\;mol^{-1}$ the normal freezing point of the solvent would be about

asked Aug 6, 2014 by meena.p

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A sample of sulphuric acid is 98% $H_2SO_4$ by weight (density =$1.10gmL^{-1})$.Calculate Molarity

asked Aug 6, 2014 by sreemathi.v

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For water , $ \Delta _{fus} H^3_m=2.74 \;kJ\;mol^{-1}$ and its molar mass is $ 84.2\;g \;mol^{-1} $ the normal freezing point depression constant at 1 atm pressure would be about

asked Aug 6, 2014 by meena.p

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1.8g of glucose (molar mass =180) are dissolved in 60g of water.Calculate the mole fraction of glucose and water

asked Aug 6, 2014 by sreemathi.v

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1.8g of glucose (molar mass =180) are dissolved in 60g of water.Calculate the molality

asked Aug 6, 2014 by sreemathi.v

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1.23g of sodium hydroxide (molar mass =40) are dissolved in water and the solution is made to $100cm^3$.Calculate the molarity of solution.

asked Aug 6, 2014 by sreemathi.v

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When $20\;g$ of naphthoic acid $(C_{11}H_gO_2)$ is dissolved in $50 \;g$ of benzene $(K_t =1.72\;K\;kg\;mol^{-1}).$, a freezing point depression of $2 K$ is observe. The van't Hoff factor (i) is

asked Aug 6, 2014 by meena.p

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Determine the osmotic pressure of a solution prepared by dissolving 25 mg of $K_2SO_4$ in 2 litre of water at 25$^{\large\circ}$ C, assuming that it is completely dissociated.

asked Aug 6, 2014 by sreemathi.v

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The unit of freezing point depression constant is

asked Aug 6, 2014 by meena.p

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The freezing point of a $0.05$ molal solution of a nonelectrolyte in water is

asked Aug 6, 2014 by meena.p

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Determine the amount of $CaCl_2$ (i = 2.47) dissolved in 2.5 litre of water such that its osmotic pressure is 0.75 atm at 27$^{\large\circ}$ C.

asked Aug 6, 2014 by sreemathi.v

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The molar mass of acetic acid dissolved in benzene determined from the depression in freezing point is found to be

asked Aug 6, 2014 by meena.p

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The freezing point of equimolal solution will be lowest for

asked Aug 6, 2014 by meena.p

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Which of the following exhibits the greater freezing - point lowering ?

asked Aug 6, 2014 by meena.p

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The air is a mixture of a number of gases. The major components are oxygen and nitrogen with approximate proportion of 20% is to 79% by volume at 298 K. The water is in equilibrium with air at a pressure of 10 atm. At 298 K if the Henry’s law constants for oxygen and nitrogen at 298 K are $3.30 \times 10^7$ mm and $6.51 \times 10^7$ mm respectively, calculate the composition of these gases in water.

asked Aug 6, 2014 by sreemathi.v

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When a sugar- solution is slowly frozen, the first solid which separates out is

asked Aug 6, 2014 by meena.p

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Benzene and toluene form ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at 300 K are 50.71 mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene in vapour phase if 80 g of benzene is mixed with 100 g of toluene.

asked Aug 6, 2014 by sreemathi.v

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Vapour pressures of pure acetone and chloroform at 328 K are 741.8 mm Hg and 632.8 mm Hg respectively. Assuming that they form ideal solution over the entire range of composition, plot $p_{total}, p_{chloroform}$, and $p_{acetone}$ as a function of $x_{acetone}$. The experimental data observed for different compositions of mixture is:

asked Aug 6, 2014 by sreemathi.v

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100 g of liquid A (molar mass $140 g mol^{–1}$) was dissolved in 1000 g of liquid B (molar mass $180 g mol^{–1}$). The vapour pressure of pure liquid B was found to be 500 torr. Calculate the vapour pressure of pure liquid A and its vapour pressure in the solution if the total vapour pressure of the solution is 475 torr.

asked Aug 6, 2014 by sreemathi.v

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Henry’s law constant for the molality of methane in benzene at 298 K is $4.27 \times 10^5$ mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.

asked Aug 6, 2014 by sreemathi.v

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Pure Benzene freezes at $5.4 ^{\circ}\;C$. A solution of $0.223 \;g$ of phenyl acetic acid $(C_6 H_5 CH_2 COOH)$ in $4.4\;g$ benzene $(K_f =5.12 K\; Kg\;mol^{-1}) $ freezes at $4.47 ^{\circ}$ . From this observation , one can conclude that

asked Aug 5, 2014 by meena.p

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Assuming $ 100\%$ ionization , the increasing order of the freezing point of the solution will be

asked Aug 5, 2014 by meena.p

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A solution contains $0.1 \; mol$ of acetamide in 1L of glacial acetic acid . When the solution is cooled , the first crystals that appeared at the freezing point contain the molecules of

asked Aug 5, 2014 by meena.p

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For an ideal solution containing a nonvolatile solute, Which of the following expression is correctly represented?

asked Aug 5, 2014 by meena.p

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The freezing point of equimolal aqueous solution will be highest for

asked Aug 5, 2014 by meena.p

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Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.

asked Aug 5, 2014 by sreemathi.v

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Which of the following $0.1 \;M$ aqueous solution will have the lowest freezing point ?

asked Aug 5, 2014 by meena.p

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When mercuric iodide is added to an aqueous solution of potassium iodide the

asked Aug 5, 2014 by meena.p

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$5 g$ of a nonvolatile compound (molar mass $50\; g \;mol^{-1}$) is added to 100 g of water . If the decrease of pressure is $11.31$ Torr, the vapour pressure of water will be

asked Aug 5, 2014 by meena.p

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19.5 g of $CH_2FCOOH$ is dissolved in 500 g of water. The depression in the freezing point of water observed is 1.00$^{\large\circ}$ C. Calculate the van’t Hoff factor and dissociation constant of fluoroacetic acid.

asked Aug 5, 2014 by sreemathi.v

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Calculate the depression in the freezing point of water when 10 g of $CH_3CH_2CHClCOOH$ is added to 250 g of water. $K_a = 1.4 \times 10^{–3}, K_f = 1.86 K kg mol^{–1}$.

asked Aug 5, 2014 by sreemathi.v

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The vapour pressure of a solvent is found to be $400 mm$ Hg at $300 K$ When a certain amount of nonvolatile solute added to $50\;mol$ of the solvent its vapour pressure decreases to $360\;mm Hg$. The amount of solute added is:

asked Aug 5, 2014 by meena.p

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The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.

asked Aug 5, 2014 by sreemathi.v

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Calculate the amount of benzoic acid $(C_6H_5COOH)$ required for preparing 250 mL of 0.15 M solution in methanol.

asked Aug 5, 2014 by sreemathi.v

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Nalorphene $(C_{19}H_{21}NO_3)$, similar to morphine, is used to combat withdrawal symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg. Calculate the mass of $1.5 \times 10^{–3} m$ aqueous solution required for the above dose.

asked Aug 5, 2014 by sreemathi.v

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Calculate the mass percentage of aspirin ($C_9H_8O_4$) in acetonitrile ($CH_3CN$) when 6.5 g of $C_9H_8O_4$ is dissolved in 450 g of $CH_3CN$.

asked Aug 5, 2014 by sreemathi.v

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If the solubility product of CuS is $6 \times 10^{–16}$, calculate the maximum molarity of CuS in aqueous solution.

asked Aug 5, 2014 by sreemathi.v

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If the density of some lake water is $1.25g mL^{–1}$ and contains 92 g of $Na^+$ ions per kg of water, calculate the molality of $Na^+$ ions in the lake.

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? Pentanol.

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? $CHCl_3$

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? Ethylene glycol

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? Formic acid

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? Toluene

asked Aug 5, 2014 by sreemathi.v

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In the following compound, identify is it insoluble, partially soluble and highly soluble in water? Phenol

asked Aug 5, 2014 by sreemathi.v

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Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain. Cyclohexane, KCl, $CH_3OH, CH_3CN$.

asked Aug 5, 2014 by sreemathi.v

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