Equilibrium: Chemical and Physical Processes - Class XI
Chemical equilibrium, Le Chatelier's principle, phase equilibrium, and solution properties including Raoult's law
Questions
An equilibrium expression may be forced to completion by:
- adding a catalyst
- increasing the pressure
- increasing the temperature
- removing the products from the reaction mixture as they are formed
- decreasing the reactant concentration
${N} _{2}(g)+3{H} _{2}(g)\rightleftharpoons 2{NH} _{3}(g)+heat$
For the reaction above, what is the effect on the equilibrium position when the pressure is decreased?
- Increased production of products
- Increased production of reactants
- Fluctuations in the amounts of reactants and products
- No impact on the equilibrium
- Cannot be determined
In a closed container rates of evaporation and condensation are same. What this statement indicate?
- A general rule for predicting solubility
- Conversion of solid phase to the liquid phase
- It represents relationship between absolute temperature and the kinetic energy of particles
- It represents relationship between volume and temperature at constant pressure
- A state in which the liquid and gas phases are in equilibrium
Which of the following solutions show positive deviation from Raoult's law?
- Acetone + Ethanol
- Acetone + Benzene
- Water + Methanol
- All of the above
Ideal solutions doesn't obey Roult's law.
- True
- False
An increase in pressure will change the equilibrium by:
- shifting to the side where a smaller volume results
- shifting to the side where a larger volume results
- favoring the endothermic reaction
- favoring the exothermic reaction
- none of the above
Which of the following is false of a binary solution showing false deviation from Roult's law?
- $P _A < X _AP _A^o$
- $\Delta H _{mix} < 0$
- $\Delta V _{mix} < 0$
- None of the above
Volume of mixing for a liquid solution is :
- may be positive or negative depending on the nature of liquids
- 0
- +ve
- -ve
What is not something that a phase equilibrium line shows?
- The equilibrium point between solid and liquid
- The equilibrium point between liquid and gas
- The equilibrium point between liquid and solid
- The equilibrium point between solid and gas
- The equilibrium point between gas and vapor
Which of the following solutions does not show positive deviation?
- Acetone and Ethanol
- Toluene and Benzene
- Water and Ethanol
- Water and Methanol
At 373 K, steam and water are in equilibrium and $\Delta H$ = 40.98 kJ $mol^{-1}$.What will be $\Delta S$ fro conversion of water into steam?
$H _2O _{(l)} \rightarrow H _2O _{(g)}$
- 109.8 J $K^{-1}mol^{-1}$
- 31 J $K^{-1}mol^{-1}$
- 21.98 J $K^{-1}mol^{-1}$
- 326 J $K^{-1}mol^{-1}$
At what temperature liquid water will be in equilibrium with water vapour?
$\Delta H _{vap} = 40.73 \ kJ \ mol^{-1}$, $\Delta S _{vap} = 0.109 \ kJ \ K^{-1} \ mol^{-1}$,
- 282.4 K
- 373.6 K
- 100 K
- 400 K
In physical equilibrium, forces responsible for equilibrium are _______ in nature.
- physical
- chemical
- strong
- weak
Which of the following represent physical equlibrium?
- Dissolution of solid $KI$ in water
- Sublimation of $NH _4Cl$
- Evaporation of dry ice in a closed container
- Condesation of water vapours
A yellow precipitate obatined in II group of the equilibrium analysis was soluble in aq. $NaOH$ and insoluble in dil. $HNO _3$. This shows the presence of:
- $Tin$
- $Antimony$
- $Arsenic$
- $Cadmium$
Which of the following statements is incorrect ?
- In equilibrium mixture of ice water kept in perfectly insulated flask mass of ice and water does not change with time .
- The intensity of red colour increase when oxalic acid is added to a solution containing iron (III) nitrate and potassium thioyanate .
- On addition of catalyst equilibrium constant value is not affected .
- Equilibrium constant for a reaction with negative $\triangle H$ value decreases as the temperature increases .
Two flasks A and B of an equal volume containing 1 mole and 2 moles of O$ _3$ respectively are heated to the same temperature. When the reaction $2O _3 \rightleftharpoons 3O _2$ practically stops, then both the flasks shall have ___________.
- the same ratio: $[O _2]/[O _3]$
- the same ratio: $[O _2]^{3/2}/[O _3]$
- only $O _2$
- the same time to reach equilibrium
Which of the following is not a general characteristic of equilibrium involving physical processes ?
- equilibrium is possible only in a closed system at a given temperature .
- all measurable properties of the system remain constant .
- all the physical processes stop at equilibrium.
- the opposing processes occur at the same ratio and there is dynamic but stable condition .