Which of the following pairs constitutes a buffer?
- $ HNO_2$ & $ NaNO_2 $
- $ NaOH$ & $ NaCl $
- $ HNO_3$ & $ NH_4NO_3 $
- $ HCl$ & $KCl $
The Correct Option is A
Approach Solution - 1
HNO2 and NaNO2 constitutes a buffer solution. Buffer solutions are a mixture of weak acids and their salts or weak bases and their salts. Among all the compounds mentioned above HCl and HNO3 are strong acids and NaOH is a a strong base. Therefore, these can not form buffer solutions. On the other hand, HNO2 is a weak acid and NaNO2 is the salt formed by HNO2 and NaOH. Hence, these constitute a buffer solution. Buffer solutions can resist a change in their pH because of the equilibrium between the acid and its conjugate base or base and its conjugate acid.
Approach Solution -2
A buffer solution is a solution that can resist changes in \(pH\) when a small amount of an acid or a base is added to it. A buffer solution typically contains a weak acid and its corresponding conjugate base, or a weak base and its corresponding conjugate acid.
Out of the given pairs, only \(HNO_2\) and \(NaNO_2\) constitute a buffer.
\(HNO_2\) is a weak acid and \(NaNO_2\) is its conjugate base. When combined, they form a buffer solution that can resist changes in pH.
\(NaOH\) and \(NaCl\) do not constitute a buffer because \(NaOH\) is a strong base and \(NaCl\) is a salt, neither of which can act as a weak acid or weak base.
\(HNO_3\) and \(NH_4NO_3\) do not constitute a buffer because \(HNO_3\) is a strong acid, and \(NH_4NO_3\) is a salt, neither of which can act as a weak acid or weak base.
\(HCl\) and \(KCl\) do not constitute a buffer because \(HCl\) is a strong acid, and \(KCl\) is a salt, neither of which can act as a weak acid or weak base.
Top Questions on Equilibrium
- Which of the following statements is false?
- VITEEE - 2024
- Chemistry
- Equilibrium
- Phenol does not undergo nucleophilic substitution reaction easily due to:
- VITEEE - 2024
- Chemistry
- Equilibrium
- For the given reaction, choose the correct expression of \(K_c\) from the following: \(Fe_{(aq)}^{3+}+SCN_{(aq)}^{−}⇌(FeSCN)_{(aq)}^{2+}\)
- JEE Main - 2024
- Chemistry
- Equilibrium
- Given below are two statements:
Statement (I): Aqueous solution of ammonium carbonate is basic.
Statement (II): Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on \( K_a \) and \( K_b \) value of acid and the base forming it.
In the light of the above statements, choose the most appropriate answer from the options given below:- JEE Main - 2024
- Chemistry
- Equilibrium
- The pH at which Mg(OH)\(_2\) \([K_{sp} = 1 \times 10^{-11}]\) begins to precipitate from a solution containing 0.10 M Mg\(^{2+}\) ions is \( \_\_\_\_ \).
- JEE Main - 2024
- Chemistry
- Equilibrium
Questions Asked in NEET exam
- Match List I with List II:Choose the correct answer from the options given below:
List I
List II
A Pterophyllum I Hag fish B Myxine II Saw fish C Pristis III Angel fish D Exocoetus IV Flying fish - NEET (UG) - 2024
- Nomenclature and taxonomy
- In an ecosystem if the Net Primary Productivity (NPP) of first trophic level is 100x (kcal m-2)yr-1, what would be the GPP (Gross Primary Productivity) of the third trophic level of the same ecosystem?
- NEET (UG) - 2024
- Ecosystems
- Identify the correct option (A), (B), (C), (D) with respect to spermatogenesis.
- NEET (UG) - 2024
- Organ And Organ System
- \(^{290}_{82}X\stackrel{\alpha}{\rightarrow}Y\stackrel{e^+}{\rightarrow}Z\stackrel{\beta^-}{\rightarrow}P\stackrel{e^-}{\rightarrow}Q\)
In the nuclear emission stated above, the mass number and atomic number of the product Q respectively, are :- NEET (UG) - 2024
- Nuclear physics
- Match List I with List II.Choose the correct answer from the options given below:
List I
(Spectral Lines of Hydrogen for transitions from)List II
(Wavelength (nm))A. n2 = 3 to n1 = 2 I. 410.2 B. n2 = 4 to n1 = 2 II. 434.1 C. n2 = 5 to n1 = 2 III. 656.3 D. n2 = 6 to n1 = 2 IV. 486.1 - NEET (UG) - 2024
- Bohr’s Model for Hydrogen Atom
Concepts Used:
Equilibrium
An equilibrium represents a state in a process when the observable properties such as color, temperature, pressure, concentration etc do not show any change.
The word equilibrium means ‘balance’ which indicates that a chemical reaction represents a balance between the reactants and products taking part in the reaction. The equilibrium state is also noticed in certain physical processes such as the melting point of ice at 0℃, both ice and water are present at equilibrium.
In the case of physical processes such as the melting of solid, dissolution of salt in water etc., the equilibrium is called physical equilibrium while the equilibrium associated with chemical reaction is known as chemical equilibrium.
Equilibrium in Chemical changes
The chemical equilibrium in a reversible reaction is the state at which both forward and backward reactions occur at the same speed.
The stage of the reversible reaction at which the concentration of the reactants and products do not change with time is called the equilibrium state.
Read More: Calculating Equilibrium Concentration
Types of Chemical Equilibrium
There are two types of chemical equilibrium:
- Homogeneous Equilibrium
- Heterogeneous Equilibrium
Homogenous Chemical Equilibrium
In this type, the reactants and the products of chemical equilibrium are all in the same phase. Homogenous equilibrium can be further divided into two types: Reactions in which the number of molecules of the products is equal to the number of molecules of the reactants. For example,
- H2 (g) + I2 (g) ⇌ 2HI (g)
- N2 (g) + O2 (g) ⇌ 2NO (g)
Reactions in which the number of molecules of the products is not equal to the total number of reactant molecules. For example,
- 2SO2 (g) + O2 (g) ⇌ 2SO3 (g)
- COCl2 (g) ⇌ CO (g) + Cl2 (g)
Heterogeneous Chemical Equilibrium
In this type, the reactants and the products of chemical equilibrium are present in different phases. A few examples of heterogeneous equilibrium are listed below.
- CO2 (g) + C (s) ⇌ 2CO (g)
- CaCO3 (s) ⇌ CaO (s) + CO2 (g)
Thus, the different types of chemical equilibrium are based on the phase of the reactants and products.
Check Out: Equilibrium Important Questions