Equilibrium Flashcards by Dr Menaka Raut

Ion exchange reactions may be reversible if there is no……….. and ………….. on any side

Solid
Gaseous
Solids are precipitated and gases get evaporated

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Hydrazoic acid is

N3H
It dissociates into H+ and N3-

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Acidic strength of hydroxy acids is direct proportional to………..

Electronegativity of central atom and oxidation state of central atom

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Species that will easily accept H+ ion must be…….

Easily donate lone pair of electron thus having low electronegativity
Should not have d subshells

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Equilibrium can be established for both physical
processes and chemical reactions.

True

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Based on the extent to which the reactions proceed to reach the state of chemical equilibrium, these may be classified in three groups.

(I) The reactions that proceed nearly
to completion and only negligible
concentrations of the reactants are
left. In some cases, it may not be even
possible to detect these experimentally.
(ii) The reactions in which only small
amounts of products are formed and
most of the reactants remain unchanged
at equilibrium stage.
(iii) The reactions in which the concentrations
of the reactants and products are
comparable, when the system is in
equilibrium.

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Assertion: Equilibrium is not static. The intense activity can be noticed at the boundary between ice and water.
Reason Molecules from the liquid water collide against ice and
adhere to it and some molecules of ice escape
into liquid phase.

Both are correct and correct explanation

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Statement 1: Physical equilibrium can only be attained in close vessel
Statement 2: Some Changes take place at molecular level in physical equilibrium

1 is correct and 2 is incorrect

No changes occur at molecular level

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Give two Drying agent

anhydrous calcium chloride
phosphorus penta-oxide

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Characteristic of equilibrium

Equilibrium can be established only in case of closed system.
The equilibrium is always dynamic in nature.
All measurable properties of the system become constant at equilibrium.
At equilibrium, there exists an expression involving concentration of reacting substances which becomes constant at a given temperature.
The magnitude of the constant value of the concentration related expression called equilibrium constant) gives an indication of the extent to which the reaction has proceeded before acquiring equilibrium

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Vapour pressure of water………….with temperature.

increases

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Time taken for complete evaporation depends on
3 things

(i) the nature of the liquid
(ii) the amount of the liquid
(iii) the temperature.

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For any pure liquid at one atmospheric pressure (1.013 bar), the temperature at which the liquid and vapours are at equilibrium is called normal……..point of the liquid.

boiling

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Statement 1: Boiling point of the liquid depends on the atmospheric pressure.
Statement 2: It depends on
the altitude of the place; at high altitude the
boiling point decreases.

Both are correct

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Statement 1: The concentration of the solute in a saturated
solution depends upon the temperature.
Statement 2: In a saturated solution, a dynamic equilibrium
exits between the solute molecules in the solid
state and in the solution

Both are correct

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Assertion: When a soda water bottle is opened, some of
the carbon dioxide gas dissolved in it fizzes
out rapidly.
Reason:The phenomenon arises due
to difference in solubility of carbon dioxide
at different pressures.

Both are correct and correct explanation

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The soda water bottle is sealed
under pressure of gas when its solubility in
water is low

False
Solubility in water is high

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Norwegian chemists Cato Maximillian Guldberg and Peter Waage proposed in 1864 proposed the law of………

Mass action

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Law of mass action states

It states that the rate of a chemical reaction is directly proportional to the product of active masses of the reacting substances raised to the power equal to the stoichiometric coefficient in the balanced chemical equation.

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Equilibrium Law or Law of Chemical
Equilibrium.

At a given temperature, the product of concentrations of the reaction products raised to the respective stoichiometric coefficient in the balanced chemical equation divided by the product of concentrations of the reactants raised to their individual stoichiometric coefficients
has a constant value.

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In a…………system, all the reactants and products are in the same phase.

homogeneous

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Equilibrium in a system having more than one phase is called……….equilibrium.

heterogeneous

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Equilibrium constants can also be expressed as dimensionless quantities if the standard state of reactants and products are specified.
True or false

True

On hydrolysis in NaHCO3 it produces NaOH

A: Acudic Sol
B: Alkaline Sol
C: Slightly Alkaline
D:NOT

Slightly Alkaline
On hydrolysis with water it produces NaOH and H2CO3
Here NaOH dissociates to produce OH- ions thus making it basic theoretical
But the abnormality arises due to dissociation of H2CO3 and it produces H+ and CO3 2- ions
Theses H+ ions decrease the alkalinity of the solution by reacting with the OH- ions Theses H
Though the H+ are released they aren’t in that high concentration to cross the OH- concentration thus the solution becomes SLIGHTLY ALKALINE in nature

NaHSO3 on hydrolysis give A: Basic Sol B: Slightly Acidic C: Slightly Basic D: NOT

Slightly acidic On hydrolysis these produce NaOH (SB) and H2SO3 (WA) NaOH produces OH- and H2SO3 dissociates to produce H+ and SO3 2- Here these H+ produced decrease the amount of OH- ions by reacting with them and this is large in amount as the H+ surpass the amount of OH- thus making the solution SLIGHTLY ACIDIC while it was expected to be basic on basis of NaOH being strong base and H2SO3 a weak acid

NO2 gas is………. in colour whereas when it dimerises to form N2O4 it becomes……..

Brown Colourless

The reaction of dimerisation of NO2 is ………..

Exothermic It can be used to depict effect of temperature on equilibrium At freezing temperatures the reaction favoured in forward direction and thus brown colour fades and at high temperatures it is not favoured as it is Exothermic and thus the brown colour of NO2 intensifies

[Co(H2O)6 ]^3+(aq) + 4Cl–(aq) <—EQB—> [CoCl4 ]^2–(aq) + 6H2O(l) ∆H is +ve In this reaction at room temperature the equilibrium mixture is blue due to………… and on cooling it turns pink due to…………

[CoCl4 ]^2– [Co(H2O)6 ]^3+

The manufacturing of sulphuric acid by……….

contact process 2SO2 (g) + O2 (g) <—EQB—>2SO3 (g); K c = 1.7 × 10^26

Hydrochloric acid present in the gastric juice is secreted by the lining of our stomach in a significant amount of……… per day and is essential for digestive processes.

1.2-1.5 L/day

Lemon and orange juices contain……./……… acids and………. is found in tamarind paste.

citric and ascorbic acids tartaric acid

He who was very famous for his Christmas lecture on the ‘Chemical History Of Candle’

Michael Faraday

…………… refers to the process of separation of ions in water already existing as such in the solid state of the solute, as in sodium chloride. On the other hand……….. corresponds to a process in which a neutral molecule splits into charged ions in the solution. In chapter these words are used interchangeably

Dissociation ionization

The Brönsted Lowry theory of acid base was given by

Danish chemist Johannes Brönsted English chemist Thomas M. Lowry

G.N. Lewis in 1923 gave the ……….. theory

Lewis acid base theory

Certain water soluble organic compounds like………/………behave as weak acids and exhibit different colours in their acid (HIn) and conjugate base (In– ) forms.

phenolphthalein and bromothymol blue

The pH in the range of 1-14 can be determined with an accuracy of………… using pH paper.

Nearly 0.5

For greater accuracy pH meters are used. pH meter is a device that measures the …………. of the test solution within………. precision. pH meters of the size of a writing pen.

pH-dependent electrical potential 0.001

The dissociation or ionization constant of acid and bases are dimensionless quantities

True

Assertion: Higher order ionisation constants are smaller that the lower order ionisation constants ie Ka1>Ka2>Ka3

Reason: It is more difficult to remove a positively charged proton from a negatively charged ion due to electrostatic forces

The extent of dissociation of an acid depends on the………&……..of the H-A bond.

strength and polarity

Explain the relation between how the bond strength and bond polarity affect the acidic nature

Weaker the bond lesser the energy required to break the bond thus stronger the acid More the bond becomes polar ie the electronegativity difference between them increases and this is marked by charge separation cleavage of the bond becomes even easier thereby increasing acidity

For comparing along a period for acidic nature we compare it by ……… of HA bond and in group we consider predominantly the effect of………

Bond polarity in period Bond strength in group

The degree of hydrolysis is independent of concentration of solution

True

A mixture of acetic acid and sodium acetate acts as buffer solution around pH…….

4.75

The mixture of ammonium chloride and ammonium hydroxide acts as a buffer around pH…….

9.25

Assertion: For preparing the buffer solution of the required pH we select that acid whose pKa is close to the required pH.

Reason: If the molar concentration of acid and salt (conjugate base) same, the pH of the buffer solution will be equal to the pKa of the acid.

In case of a……….. solvent, solvation enthalpy is small and hence, not sufficient to overcome the lattice enthalpy of the salt.

non-polar (covalent)

Solubility check

Soluble S> 0.1M Slightly soluble 0.01M < S < 0.1M Sparingly soluble S < 0.01M

Statement 1: A salt may give on dissociation two or more than two anions and cations carrying different charges. Statement 2: Zirconium phosphate of molecular formula (Zr4+)3 (PO4 3–)4 . It dissociates into 3 zirconium cations of charge +4 and 4 phosphate anions of charge –3.

Both are correct

If we take a saturated solution of sodium chloride and pass HCl gas through it, then sodium chloride is precipitated due to increased concentration (activity) of chloride ion available from the dissociation of HCl. The common ion effect is used here and is exploited on getting benefit of

Sodium chloride thus obtained is of very high purity and we can get rid of impurities like sodium and magnesium sulphates.

Statement 1: We can precipitate silver ion as silver chloride, ferric ion as its hydroxide (or hydrated ferric oxide) and barium ion as its sulphate for quantitative estimations. Statement 2: The common ion effect is also used for almost complete precipitation of a particular ion as its sparingly soluble salt, with very low value of solubility product for gravimetric estimation.

Both are correct

Assertion: The solubility of salts of weak acids like phosphates increases at lower pH. Reason: At lower pH the concentration of the anion decreases due to its protonation.

Both are correct and correct explanation

Codeine formula

C18H21NO3

Important question

https://www.neetprep.com/ncert-question/228616

Important NCERT question

https://www.neetprep.com/ncert-question/228618