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MCQOPTIONS
This section includes 11242 Mcqs, each offering curated multiple-choice questions to sharpen your Joint Entrance Exam - Main (JEE Main) knowledge and support exam preparation. Choose a topic below to get started.
| 4101. |
The relative lowering of vapour pressure produced by dissolving 71.5 g of a substance in 1000 g of water is 0.00713. The molecular weight of the substance will be [DPMT 2001] |
| A. | 18.0 |
| B. | 342 |
| C. | 60 |
| D. | 180 |
| Answer» E. | |
| 4102. |
In an experiment, 1 g of a non-volatile solute was dissolved in 100 g of acetone (mol. mass = 58) at 298K. The vapour pressure of the solution was found to be 192.5 mm Hg. The molecular weight of the solute is (vapour pressure of acetone = 195 mm Hg) [CPMT 2001; CBSE PMT 2001; Pb CET 2002] |
| A. | 25.24 |
| B. | 35.24 |
| C. | 45.24 |
| D. | 55.24 |
| Answer» D. 55.24 | |
| 4103. |
How many grams of \[C{{H}_{3}}OH\] should be added to water to prepare \[150\,ml\] solution of \[2\,M\,C{{H}_{3}}OH\] [CBSE PMT 1994] |
| A. | 9.6 |
| B. | 2.4 |
| C. | \[9.6\times {{10}^{3}}\] |
| D. | \[2.4\times {{10}^{3}}\] |
| Answer» B. 2.4 | |
| 4104. |
60 gm of Urea (Mol. wt 60) was dissolved in 9.9 moles, of water. If the vapour pressure of pure water is \[{{P}_{o}}\], the vapour pressure of solution is [DCE 2000] |
| A. | 0.10 \[{{P}_{o}}\] |
| B. | 1.10 \[{{P}_{o}}\] |
| C. | 0.90 \[{{P}_{o}}\] |
| D. | 0.99 \[{{P}_{o}}\] |
| Answer» D. 0.99 \[{{P}_{o}}\] | |
| 4105. |
The vapour pressure of water at \[{{20}^{o}}C\] is 17.54 mm. When 20g of a non-ionic, substance is dissolved in 100g of water, the vapour pressure is lowered by 0.30 mm. What is the molecular weight of the substances [UPSEAT 2001] |
| A. | 210.2 |
| B. | 206.88 |
| C. | 215.2 |
| D. | 200.8 |
| Answer» C. 215.2 | |
| 4106. |
Which has maximum vapour pressure [DPMT 2001] |
| A. | HI |
| B. | HBr |
| C. | HCl |
| D. | HF |
| Answer» D. HF | |
| 4107. |
The vapour pressure of benzene at a certain temperature is \[640\,mm\] of \[Hg\]. A non-volatile and non-electrolyte solid weighing \[2.175g\] is added to \[39.08g\] of benzene. The vapour pressure of the solution is \[600mm\] of \[Hg\]. What is the molecular weight of solid substance [CBSE PMT 1999; AFMC 1999] |
| A. | 49.50 |
| B. | 59.6 |
| C. | 69.5 |
| D. | 79.8 |
| Answer» D. 79.8 | |
| 4108. |
Which one of the following is the expression of Raoult's law |
| A. | \[\frac{p-{{p}_{s}}}{p}=\frac{n}{n+N}\] |
| B. | \[\frac{{{p}_{s}}-p}{p}=\frac{N}{N+n}\] |
| C. | \[\frac{p-{{p}_{s}}}{{{p}_{s}}}=\frac{N}{N-n}\] |
| D. | \[\frac{{{p}_{s}}-p}{{{p}_{s}}}=\frac{N-n}{N}\] |
| Answer» B. \[\frac{{{p}_{s}}-p}{p}=\frac{N}{N+n}\] | |
| 4109. |
?The relative lowering of the vapour pressure is equal to the mole fraction of the solute.? This law is called [MP PET 1997, 2001] |
| A. | Henry's law |
| B. | Raoult's law |
| C. | Ostwald's law |
| D. | Arrhenius's law |
| Answer» C. Ostwald's law | |
| 4110. |
An ideal solution was obtained by mixing methanol and ethanol. If the partial vapour pressure of methanol and ethanol are \[2.619\,kPa\] and \[4.556\,kPa\] respectively, the composition of the vapour (in terms of mole fraction) will be [Pb. PMT 1998] |
| A. | 0.635 methanol, 0.365 ethanol |
| B. | 0.365 methanol, 0.635 ethanol |
| C. | 0.574 methanol, 0.326 ethanol |
| D. | 0.173 methanol, 0.827 ethanol |
| Answer» C. 0.574 methanol, 0.326 ethanol | |
| 4111. |
?Relative lowering in vapour pressure of solution containing non-volatile solute is directly proportional to mole fraction of solute?. Above statement is [AFMC 2004] |
| A. | Henry law |
| B. | Dulong and Petit law |
| C. | Raoult's law |
| D. | Le-Chatelier's principle |
| Answer» D. Le-Chatelier's principle | |
| 4112. |
An aqueous solution of glucose was prepared by dissolving 18 g of glucose in 90 g of water. The relative lowering in vapour pressure is [KCET 2002] |
| A. | 0.02 |
| B. | 1 |
| C. | 20 |
| D. | 180 |
| Answer» B. 1 | |
| 4113. |
The vapour pressure of pure liquid A is 0.80 atm. On mixing a non-volatile B to A, its vapour pressure becomes 0.6 atm. The mole fraction of B in the solution is [MP PET 2003] |
| A. | 0.150 |
| B. | 0.25 |
| C. | 0.50 |
| D. | 0.75 |
| Answer» C. 0.50 | |
| 4114. |
The atmospheric pressure is sum of the [Kerala CET (Med.) 2002] |
| A. | Pressure of the biomolecules |
| B. | Vapour pressure of atmospheric constituents |
| C. | Vapour pressure of chemicals and vapour pressure of volatiles |
| D. | Pressure created on to atmospheric molecules |
| Answer» C. Vapour pressure of chemicals and vapour pressure of volatiles | |
| 4115. |
The vapour pressure of a liquid depends on |
| A. | Temperature but not on volume |
| B. | Volume but not on temperature |
| C. | Temperature and volume |
| D. | Neither on temperature nor on volume |
| Answer» B. Volume but not on temperature | |
| 4116. |
Which one of the statements given below concerning properties of solutions, describes a colligative effect [AIIMS 2003] |
| A. | Boiling point of pure water decreases by the addition of ethanol |
| B. | Vapour pressure of pure water decreases by the addition of nitric acid |
| C. | Vapour pressure of pure benzene decreases by the addition of naphthalene |
| D. | Boiling point of pure benzene increases by the addition of toluene |
| Answer» C. Vapour pressure of pure benzene decreases by the addition of naphthalene | |
| 4117. |
According to Raoult's law the relative lowering of vapour pressure of a solution of volatile substance is equal to [CBSE PMT 1995; BHU 2001] |
| A. | Mole fraction of the solvent |
| B. | Mole fraction of the solute |
| C. | Weight percentage of a solute |
| D. | Weight percentage of a solvent |
| Answer» C. Weight percentage of a solute | |
| 4118. |
Among the following substances the lowest vapour pressure is exerted by |
| A. | Water |
| B. | Mercury |
| C. | Kerosene |
| D. | Rectified spirit |
| Answer» C. Kerosene | |
| 4119. |
The vapour pressure lowering caused by the addition of 100 g of sucrose(molecular mass = 342) to 1000 g of water if the vapour pressure of pure water at \[{{25}^{o}}C\] is 23.8 mm Hg [RPET 1999] |
| A. | 1.25 mm Hg |
| B. | 0.125 mm Hg |
| C. | 1.15 mm Hg |
| D. | 00.12 mm Hg |
| Answer» C. 1.15 mm Hg | |
| 4120. |
A solution has a 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20°C are 440 mmHg for pentane and 120 mmHg for hexane. The mole fraction of pentane in the vapour phase would be [CBSE PMT 2005] |
| A. | 0.549 |
| B. | 0.200 |
| C. | 0.786 |
| D. | 0.478 |
| Answer» E. | |
| 4121. |
Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The parial vapour pressure of benzene at 20°C for a solution containing 78g of benzene and 46g of toluene in torr is [AIEEE 2005] |
| A. | 50 |
| B. | 25 |
| C. | 37.5 |
| D. | 53.5 |
| Answer» B. 25 | |
| 4122. |
At 300 K, when a solute is added to a solvent its vapour pressure over the mercury reduces from 50 mm to 45 mm. The value of mole fraction of solute will be |
| A. | 0.005 |
| B. | 0.010 |
| C. | 0.100 |
| D. | 0.900 |
| Answer» D. 0.900 | |
| 4123. |
The relative lowering of the vapour pressure is equal to the ratio between the number of [EAMCET 1991; CBSE PMT 1991] |
| A. | Solute moleules and solvent molecules |
| B. | Solute molecules and the total molecules in the solution |
| C. | Solvent molecules and the total molecules in the solution |
| D. | Solvent molecules and the total number of ions of the solute |
| Answer» C. Solvent molecules and the total molecules in the solution | |
| 4124. |
Which solution will show the maximum vapour pressure at 300 K [DPMT 2001] |
| A. | 1 M \[C{{}_{12}}{{H}_{22}}{{O}_{11}}\] |
| B. | 1 M \[C{{H}_{3}}COOH\] |
| C. | 1 M \[NaC{{l}_{2}}\] |
| D. | 1 M \[NaCl\] |
| Answer» B. 1 M \[C{{H}_{3}}COOH\] | |
| 4125. |
Vapour pressure of \[CC{{l}_{4}}\] at \[{{25}^{o}}C\] is \[143mm\] of \[Hg\,0.5\,gm\] of a non-volatile solute (mol. wt. = 65) is dissolved in \[100\,ml\,CC{{l}_{4}}\]. Find the vapour pressure of the solution (Density of \[CC{{l}_{4}}=1.58\,g/c{{m}^{2}}\]) [CBSE PMT 1998] |
| A. | \[141.43\,mm\] |
| B. | \[94.39\,mm\] |
| C. | \[199.34\,mm\] |
| D. | \[143.99\,mm\] |
| Answer» B. \[94.39\,mm\] | |
| 4126. |
The pressure under which liquid and vapour can coexist at equilibrium is called the |
| A. | Limiting vapour pressure |
| B. | Real vapour pressure |
| C. | Normal vapour pressure |
| D. | Saturated vapour pressure |
| Answer» C. Normal vapour pressure | |
| 4127. |
On the velocity in a reversible reaction, the correct explanation of the effect of catalyst is [MP PMT 1987] |
| A. | It provides a new reaction path of low activation energy |
| B. | It increases the kinetic energy of reacting molecules |
| C. | It displaces the equilibrium state on right side |
| D. | It decreases the velocity of backward reaction |
| Answer» B. It increases the kinetic energy of reacting molecules | |
| 4128. |
The reaction\[A+B\]⇌\[C+D\]+heat has reached equilibrium. The reaction may be made to proceed forward by [IIT 1978] |
| A. | Adding more C |
| B. | Adding more D |
| C. | Decreasing the temperature |
| D. | Increasing the temperature |
| Answer» D. Increasing the temperature | |
| 4129. |
\[{{A}_{2(g)}}+{{B}_{2(g)}}\]⇌\[2A{{B}_{(g)}}\]; \[\Delta H=+ve\] [BHU 2003] |
| A. | Unaffected by pressure |
| B. | It occurs at 1000 pressure |
| C. | It occurs at high temperature |
| D. | It occurs at high pressure and high temperature |
| Answer» B. It occurs at 1000 pressure | |
| 4130. |
For a reaction if \[{{K}_{p}}>{{K}_{c}}\], the forward reaction is favoured by [RPET 2003] |
| A. | Low pressure |
| B. | High pressure |
| C. | High temperature |
| D. | Low temperature |
| Answer» B. High pressure | |
| 4131. |
The gaseous reaction A + B ⇌ 2C + D; + Q is most favoured at [Karnataka CET 2003] |
| A. | Low temperature and high pressure |
| B. | High temperature and high pressure |
| C. | High temperature and low pressure |
| D. | Low temperature and low pressure |
| Answer» E. | |
| 4132. |
When the pressure is applied over system ice ⇌ water what will happen? [MP PMT 1990; CPMT 1983; NCERT 1978; DPMT 2002] |
| A. | More water will form |
| B. | More ice will form |
| C. | There will be no effect over equilibrium |
| D. | Water will decompose in \[{{H}_{2}}\] and \[{{O}_{2}}\] |
| Answer» B. More ice will form | |
| 4133. |
Which reaction is not effected by change in pressure [UPSEAT 2003] |
| A. | \[{{H}_{2}}+{{I}_{2}}\]⇌\[2HI\] |
| B. | \[2C+{{O}_{2}}\]⇌ 2CO |
| C. | \[{{N}_{2}}+3{{H}_{2}}\]⇌\[2N{{H}_{3}}\] |
| D. | \[PC{{l}_{5}}\]⇌\[PC{{l}_{3}}+C{{l}_{2}}\] |
| Answer» B. \[2C+{{O}_{2}}\]⇌ 2CO | |
| 4134. |
The yield of product in the reaction \[{{A}_{2(g)}}\]+ \[2{{B}_{\left( g \right)}}\]⇌ \[{{C}_{(g)}}\]+ Q.kJ. would be high at [UPSEAT 2002] |
| A. | High temperature and high pressure |
| B. | High temperature and low pressure |
| C. | Low temperature and high pressure |
| D. | Low temperature and low pressure |
| Answer» D. Low temperature and low pressure | |
| 4135. |
The chemical reaction: \[Ba{{O}_{2(S)}}\]⇌\[Ba{{O}_{(s)}}\]\[+{{O}_{2(g)}}\]? \[\Delta \]H = + ve. In equilibrium condition, pressure of O2 depends upon [CBSE PMT 2002] |
| A. | Increase mass of BaO |
| B. | Increase mass of BaO2 |
| C. | Increase in temperature |
| D. | Increase mass of BaO2 and BaO both |
| Answer» B. Increase mass of BaO2 | |
| 4136. |
The formation of nitric oxide by contact process \[{{N}_{2}}+{{O}_{2}}\] ⇌ 2NO. \[\Delta \]H = 43.200 kcal is favoured by [AMU 2002] |
| A. | Low temperature and low pressure |
| B. | Low temperature and high pressure |
| C. | High temperature and high pressure |
| D. | High temperature and excess reactants concentration |
| Answer» E. | |
| 4137. |
Which of the following will favour the reverse reaction in a chemical equilibrium [Kerala (Med.) 2002] |
| A. | Increasing the concentration of the reactants |
| B. | Removal of at least one of the products at regular intervals |
| C. | Increasing the concentration of one or more of the products |
| D. | Increasing the pressure |
| E. | None of these |
| Answer» D. Increasing the pressure | |
| 4138. |
The reaction \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}\]; \[\Delta H\] = ? ve is favoured by [CPMT 2002; Pb. PMT 2001] |
| A. | Low temperature, low pressure |
| B. | Low temperature, high pressure |
| C. | High temperature, high pressure |
| D. | High temperature, low pressure |
| Answer» D. High temperature, low pressure | |
| 4139. |
In the equilibrium N2 + 3H2 ⇌ 2NH3 + 22 kcal, the formation of ammonia is favoured by [MP PET 2000, 02] |
| A. | Increasing the pressure |
| B. | Increasing the temperature |
| C. | Decreasing the pressure |
| D. | Adding ammonia |
| Answer» B. Increasing the temperature | |
| 4140. |
The rate of reaction of which of the following is not affected by pressure [MP PMT 2002] |
| A. | \[PC{{l}_{3}}+C{{l}_{2}}\]⇌\[PC{{l}_{5}}\] |
| B. | \[{{N}_{2}}+3{{H}_{2}}\]⇌\[2N{{H}_{3}}\] |
| C. | \[{{N}_{2}}+{{O}_{2}}\]⇌ 2NO |
| D. | \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}\] |
| Answer» D. \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}\] | |
| 4141. |
\[{{H}_{2(g)}}\]+ \[{{I}_{2(g)}}\] ⇌\[2H{{I}_{(g)}}\] In this reaction when pressure increases, the reaction direction [RPMT 2002] |
| A. | Does not change |
| B. | Forward |
| C. | Backward |
| D. | Decrease |
| Answer» B. Forward | |
| 4142. |
In the following reversible reaction \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}+Q\]\[Cal\] Most suitable condition for the higher production of \[S{{O}_{3}}\] is [NCERT 1974; DPMT 1983, 89; IIT 1981; MP PET 1992; MP PMT 1990, 91, 94, 99; CPMT 1973, 77, 84, 89, 94, 99] |
| A. | High temperature and high pressure |
| B. | High temperature and low pressure |
| C. | Low temperature and high pressure |
| D. | Low temperature and low pressure |
| Answer» D. Low temperature and low pressure | |
| 4143. |
For the reaction: A + B + Q ⇌ C + D, if the temperature is increased, then concentration of the products will [AFMC 2001] |
| A. | Increase |
| B. | Decrease |
| C. | Remain same |
| D. | Become Zero |
| Answer» B. Decrease | |
| 4144. |
Le-Chatelier principle is not applicable to [MH CET 2001] |
| A. | \[{{H}_{2(g)}}+{{I}_{2(g)}}\] ⇌\[2H{{I}_{(g)}}\] |
| B. | \[F{{e}_{(S)}}+{{S}_{(S)}}\] ⇌\[Fe{{S}_{(S)}}\] |
| C. | \[{{N}_{2(g)}}+3{{H}_{2(g)}}\]⇌\[2N{{H}_{3(g)}}\] |
| D. | \[{{N}_{2(g)}}+{{O}_{2(g)}}\]⇌\[2N{{O}_{(g)}}\] |
| Answer» C. \[{{N}_{2(g)}}+3{{H}_{2(g)}}\]⇌\[2N{{H}_{3(g)}}\] | |
| 4145. |
On addition of an inert gas at constant volume to the reaction \[{{N}_{2}}+3{{H}_{2}}\]⇌\[2N{{H}_{3}}\]at equilibrium [Pb. PMT 2001] |
| A. | The reaction remains unaffected |
| B. | Forward reaction is favoured |
| C. | The reaction halts |
| D. | Backward reaction is favoured |
| Answer» B. Forward reaction is favoured | |
| 4146. |
According to Le?Chatelier?s principal adding heat to a solid and liquid in equilibrium with endothermic nature will cause the [JIPMER 2000; MP PET 2001] |
| A. | Temperature to rise |
| B. | Temperature to fall |
| C. | Amount of solid to decrease |
| D. | Amount of liquid to decrease |
| Answer» D. Amount of liquid to decrease | |
| 4147. |
Which of the following equilibrium is not shifted by increase in the pressure [MP PMT 2001] |
| A. | \[{{H}_{2}}_{(g)}+{{I}_{2}}_{(g)}\]⇌\[2H{{I}_{(g)}}\] |
| B. | \[{{N}_{2(g)}}+3{{H}_{2(g)}}\]⇌\[2N{{H}_{3}}_{(g)}\] |
| C. | \[2C{{O}_{(g)}}+{{O}_{2}}_{(g)}\]⇌\[2C{{O}_{2}}_{(g)}\] |
| D. | \[2{{C}_{(S)}}+{{O}_{2(g)}}\]⇌\[2C{{O}_{(g)}}\] |
| Answer» B. \[{{N}_{2(g)}}+3{{H}_{2(g)}}\]⇌\[2N{{H}_{3}}_{(g)}\] | |
| 4148. |
In which of the following equilibrium systems is the rate of the backward reaction favoured by increase of pressure [KCET 2001] |
| A. | \[PC{{l}_{5}}\]⇌\[PC{{l}_{3}}+C{{l}_{2}}\] |
| B. | \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}\] |
| C. | \[{{N}_{2}}+3{{H}_{2}}\]⇌\[2N{{H}_{3}}\] |
| D. | \[{{N}_{2}}+{{O}_{2}}\]⇌\[2NO\] |
| Answer» B. \[2S{{O}_{2}}+{{O}_{2}}\]⇌\[2S{{O}_{3}}\] | |
| 4149. |
\[{{H}_{2(g)}}+{{I}_{2(g)}}\]⇌\[2H{{I}_{(g)}}\,\,\,\Delta H=+q\]cal, then formation of HI: [AMU 2000] |
| A. | Is favoured by lowering the temperature |
| B. | Is favoured by increasing the pressure |
| C. | Is unaffected by change in pressure |
| D. | Is unaffected by change in temperature |
| Answer» D. Is unaffected by change in temperature | |
| 4150. |
In the equilibrium \[AB\]⇌\[A+B\]; if the equilibrium concentration of A is doubled, the equilibrium concentration of B would become: [AMU 2000] |
| A. | Twice |
| B. | Half |
| C. | 1/4th |
| D. | 1/8th |
| Answer» C. 1/4th | |