Tag: chemistry

Questions Related to chemistry

An equilibrium expression may be forced to completion by:

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

  1. adding a catalyst

  2. increasing the pressure

  3. increasing the temperature

  4. removing the products from the reaction mixture as they are formed

  5. decreasing the reactant concentration

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Correct Option: D
Explanation:

According to Le-chatelier principal reaction moves in forward direction if we remove products with time.so removing the products from the reaction mixture as they are formed may be forced to completion of an equilibrium expression.

${N} _{2}(g)+3{H} _{2}(g)\rightleftharpoons 2{NH} _{3}(g)+heat$
For the reaction above, what is the effect on the equilibrium position when the pressure is decreased?

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

  1. Increased production of products

  2. Increased production of reactants

  3. Fluctuations in the amounts of reactants and products

  4. No impact on the equilibrium

  5. Cannot be determined

Show answer
Correct Option: B
Explanation:

The given reaction is :-

${ N } _{ 2 }\left( g \right) +3{ H } _{ 2 }\left( g \right) \rightleftharpoons 2{ NH } _{ 3 }\left( g \right) +heat$
In this equilibrium, the forward reaction is accompanied by decrease in total no. of moles of gaseous species. If pressure on the system is decreased, the equilibrium shifts to the direction in which no. of moles increases as per Le Chatelier's principle. So, the backward reaction is favoured and reactants production is increased.

In a closed container rates of evaporation and condensation are same. What this statement indicate?

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

  1. A general rule for predicting solubility

  2. Conversion of solid phase to the liquid phase

  3. It represents relationship between absolute temperature and the kinetic energy of particles

  4. It represents relationship between volume and temperature at constant pressure

  5. A state in which the liquid and gas phases are in equilibrium

Show answer
Correct Option: E
Explanation:

Evaporation is the process of conversion from a liquid state to gaseous state.

Condensation is the process of conversion from the gaseous state to a liquid state. If a rate of the evaporation rate of condensation 
$\Rightarrow \quad $ Liquid & gas phases are in equilibrium.
This is the condition for physical equilibrium.

Which of the following solutions show positive deviation from Raoult's law?

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

  1. Acetone + Ethanol

  2. Acetone + Benzene

  3. Water + Methanol

  4. All of the above

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Correct Option: D

Ideal solutions doesn't obey Roult's law.

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

  1. True

  2. False

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Correct Option: B
Explanation:

Ideal solutions obey Raoult's law. Raoult's law states that the partial vapour pressure of each component an Ideal solution is equal to the vapour pressure of the pure component at that temperature multiplied by its mole fraction.

An increase in pressure will change the equilibrium by:

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

  1. shifting to the side where a smaller volume results

  2. shifting to the side where a larger volume results

  3. favoring the endothermic reaction

  4. favoring the exothermic reaction

  5. none of the above

Show answer
Correct Option: A
Explanation:

An increase in pressure will change the equilibrium by shifting to the side from higher number of moles to lower number of moles. 

Which of the following is false of a binary solution showing false deviation from Roult's law?

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

  1. $P _A < X _AP _A^o$

  2. $\Delta H _{mix} < 0$

  3. $\Delta V _{mix} < 0$

  4. None of the above

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Correct Option: D

Volume of mixing for a liquid solution is :

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

  1. may be positive or negative depending on the nature of liquids

  2. 0

  3. +ve

  4. -ve

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Correct Option: A

What is not something that a phase equilibrium line shows?

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

  1. The equilibrium point between solid and liquid

  2. The equilibrium point between liquid and gas

  3. The equilibrium point between liquid and solid

  4. The equilibrium point between solid and gas

  5. The equilibrium point between gas and vapor

Show answer
Correct Option: E
Explanation:

The phase equilibrium line does not show the equilibrium point between gas and vapor.
Because the gas and vapor belongs to the same phase.


The correct option is $E$.

Which of the following solutions does not  show positive deviation? 

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

  1. Acetone and Ethanol

  2. Toluene and Benzene

  3. Water and Ethanol

  4. Water and Methanol

Show answer
Correct Option: B