Chemistry

Solutions and Vapour Pressure

60 Questions

Solutions and vapour pressure questions explore boiling points, colligative properties, and osmotic pressure. These concepts are regularly tested in competitive chemistry exams. Solving these requires a solid grasp of solute and solvent interactions.

colligative propertiesvapour pressureboiling and melting pointsosmotic pressure

Solutions and Vapour Pressure Questions

Multiple choice

Covalent compounds are usually soluble in _______.

  1. water

  2. organic solvents

  3. both 1 and 2

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Covalent compounds are generally non-polar or weakly polar, making them more soluble in organic solvents (like benzene or ether) than in water, which is a highly polar solvent.

Multiple choice

Ionic compounds are usually soluble in ______.

  1. ether

  2. benzene

  3. water

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ionic compounds are polar in nature and dissolve readily in polar solvents like water due to the hydration energy overcoming the lattice energy. They are generally insoluble in non-polar solvents like ether or benzene.

Multiple choice

What are the melting and boiling points of liquid HCl?

  1. Boiling point: - 83�C and melting point: -113�C

  2. Boiling point: 93�C and melting point: 86�C

  3. Boiling point: 82�C and melting point: - 30�C

  4. Boiling point 113�C and melting point - 90�C
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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Multiple choice

The osmotic pressure of 5% sol of sucrose (M.M = 342) at 150 0 C, is

  1. 5.07 atm

  2. 5.007 atm

  3. 50.07 atm

  4. 500.07 atm
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The 5 % sol of sucrose means that 100 cm3 of sol contains 5 g of sucrose. Here, WB = 5 g, MB = 342 n mol-1, T = 150 + 273 = 423K, V = 0.100L, R = 0.082L atm mol-1K-1$\pi$  = nB/V RT = WBRT/MBRT =  5x0.082x423/342x0.100 = 5.07 atm

Multiple choice chemistry chemical equilibrium equilibrium in physical processes introduction to equilibrium chemical equilibrium and acids-bases

At what temperature liquid water will be in equilibrium with water vapour?
$\Delta H _{vap} = 40.73 \ kJ \ mol^{-1}$, $\Delta S _{vap} = 0.109 \ kJ \ K^{-1} \ mol^{-1}$, 

  1. 282.4 K

  2. 373.6 K

  3. 100 K

  4. 400 K
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The given reaction is :-

               ${ H } _{ 2 }O\left( l \right) \rightleftharpoons { H } _{ 2 }O\left( g \right) $
Now, at equilibrium, $\triangle G=0$
Now, from fibb's free energy change equation
         $\triangle G=\triangle H-T\triangle S$
$\Rightarrow \quad \triangle H=T\triangle S$
$\Rightarrow \quad T=\dfrac { \triangle H }{ \triangle S } =\dfrac { 40.73 }{ 0.1079 } =373.6K$
$\left( \because \triangle Hrap=40.73KJ/mol,\quad \triangle Srap=0.109KJ{ K }^{ -1 }{ mol }^{ -1 } \right) $

Multiple choice chemistry hydroxy compounds and ethers physical properties of phenol physical properties of alcohols and phenols organic compounds with functional group containing oxygen (part-1)

In which of the following solvents, KI has highest solubility? The dielectric constant $(\epsilon)$ of each liquid is given in parentheses.

  1. $ C _{6}H _{6}(\epsilon =0)$
  2. $(CH _{3}) _{2}CO(\epsilon =21)$
  3. $CH _{3}OH(\epsilon =32)$
  4. $CCl _{4}(\epsilon =0)$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

KI is an ionic compound. Hence, it will be most soluble in apolar solvent, which has a high value of dielectric constant. Hence, $CH _3OH$ with the highest value of dielectric constant among the given options will provide high solubility.

Multiple choice methods of purification of organic compounds methods of purification - organic compounds organic chemistry - some basic principles and techniques organic chemistry : some basic principles and techniques chemistry biochemical techniques

 A mixture of two immiscible liquids chlorobenzene and water boils at $90^{0}C$ and an external pressure of 740.2 torr. If vapour pressure of pure water at $90^{0}C$ is 530 torr then the mole % of chlorobenzene in the distillate will be:

  1. 80%

  2. 40%

  3. 28%

  4. 60%
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using Dalton's law for steam distillation: P_total = P_water + P_chlorobenzene. 740.2 = 530 + P_chlorobenzene, so P_chlorobenzene = 210.2 torr. The mole ratio n_c/n_w = P_c/P_w = 210.2/530 = 0.396. Mole fraction of chlorobenzene = 0.396 / (1 + 0.396) = 0.283, or 28%.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

Boiling point of a substance is based on the intermolecular and intramolecular forces which in turn determine the lattice energy of a substance.
Which of the following substance would have the highest boiling point?

  1. $NaCl$
  2. $Hg$
  3. $AlF _{3}$
  4. $H _{2}O$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$NaCl$ will have the highest boiling point as it is the strongest ionic compound present in the given options. $NaCl$ have strong interionic forces as $Na^+$ and $Cl^-$ attracts each other very strongly which results in an increase in the compactness of the molecule, further its lattice enthalpy.

Multiple choice chemistry materials liquid crystals liquid state the liquid state

$510 mg$ of a liquid on vaporization in victor Mayer's apparatus displaces $67.2 ml$ of dry air (at NTP). The molecular weight of liquid is:

  1. $130$
  2. $17$
  3. $1700$
  4. $170$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As we know that $1g$ mole of any gas occupies as $22400ml$ of volume at STP

So molecular mass of compound= $\cfrac {0.510\times 22400}{67.2}$
$\Rightarrow 16.999 \approx 17$

Multiple choice chemistry materials around us and different types of houses materials around us matter and its states different states of matter

By what factor does water expand when converted into vapour at $100^o$C and $1$ atm pressure? The density of liquid water at $100^o$C and $1$ atm is $0.96$g $cm^{-3}$?

  1. $815$
  2. $2000$
  3. $1630$
  4. $500$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using the ideal gas equation for water vapour at 100 degrees C and 1 atm, calculate the molar volume of steam. Comparing this molar volume to the volume of 1 mole of liquid water based on its given density yields the expansion factor.