Chemistry

Acids and Bases

579 Questions

Acids and bases questions cover the chemical properties, common examples, and theoretical concepts of acidic and basic substances. Topics include identifying proton acceptors, recognizing amphoteric substances, and knowing the sources of everyday organic acids. These foundational chemistry questions are common across SSC, banking, and railways examinations.

Acid and base propertiesOrganic acidsAmphoteric substancesProton donors and acceptorsChemical formulas

Acids and Bases Questions

Multiple choice chemistry further aspects of equilibria dissociation constants ionisation of weak acids and weak bases ionization constants of weak acids and weak bases

When strong base $(NaOH)$ is added to the weak acid (acetic acid, ${ CH } _{ 3 }COOH$), then dissociation of acetic acid increases; this effect is known as:

  1. Common ion effect

  2. Reverse ion effect

  3. Saltation effect

  4. Solubility effect
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$CH _3COOH\rightleftharpoons CH _3COO^{-}+H^+$
When $NaOH$ is added $H^+$ combines with $OH^{-}$ so concentration of $H^+$ decreases so equilibrium will shift towards right.
${ CH } _{ 3 }COOH+NaOH\longrightarrow { CH } _{ 3 }COONa+{ H } _{ 2 }O\quad $
Ionization of acetic acid will increase with the progress of its neutralization. This effect is called reverse ion effect.

Multiple choice group 17 elements - trends in chemical properties group 17 elements - properties p- block elements-ii p-block elements chemistry

Which of the following is most acidic?

  1. $HClO$
  2. $HClO _2$
  3. $HClO _3$
  4. $HClO _4$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As the oxidation number of chlorine(non metal) increases in the given acids the acidic nature of the compound increases. So the oxidation numbers of chlorine in the given compounds are $+1,+3,5,+7$ respectively.

So the acidic nature of $HClO _4$ is high.
Hence option D is correct.

Multiple choice chemistry chemical kinetics dependence of reaction rate on concentration of reactants order of reactions factors influencing rate of a reaction

When ethyl acetate was hydrolysed in presence of 0.1 N HCl, the rate constant was found to be $5.40\times 10^{-5}sec^{-1}$. But when 0.1 N $H _2SO _4$ was used for hydrolysis, the rate constant was found to be $6.25\times 10^{-5} sec^{-1}$. Thus, it may be concluded that:

  1. $H _2SO _4$ is stronger than HCl
  2. $H _2SO _4$ is weaker than HCl
  3. $H _2SO _4$ and HCl both have the same strength
  4. the data are not sufficient to compare the strength of $H _2SO _4$ and HCl
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option (A) is correct.  $H _2SO _4$ is stronger than $HCl$.
Relative strength in favour of $H _2SO _4$
$=\frac {\text {rate constant of reaction catalysted by }H _2SO _4}{\text {rate constant of reaction catalysted by HCl}}$.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Acidic oxides react with water to give ________.

  1. base

  2. acids

  3. salt

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Acids are formed by reacting acidic oxides with water. $CO _2$ is acidic oxide. On reacting it with water, $H _2CO _3$, which is an acid forms.
$CO _2 + H _2O \rightarrow H _2CO _3$
                                 $acid$
Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen

Which of the following is the most acidic?

  1. ${ P } _{ 2 }{ O } _{ 5}$
  2. ${ N } _{ 2 }{ O } _{ 5 }$
  3. ${ Sb } _{ 2 }{ O } _{ 5 }$
  4. ${ As } _{ 2 }{ O } _{ 5 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As the electronegativity value of the element increases. the acidic character of the oxide also increases.

Here among $N,P,SI$ and $As$ the most electronegative is $N$.

Thus the most acidic is $N _2O _5$.

Multiple choice chemistry chemistry of non-metals oxides of elements simple oxides oxygen
Amphoteric species is:
  1. $Na _3PO _4$
  2. $HSO _4^-$
  3. $KOH$
  4. $HNO _3$
  5. $C _2O^{2-} _4$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Amphoteric specie is $\displaystyle HSO _4^-$.
It reacts with acid as well as base.
$\displaystyle HSO _4^- + H^+ \rightarrow H _2SO _4$
$\displaystyle HSO _4^-+ OH^- \rightarrow SO _4^{2-} + H _2O$