Tag: chemistry

Questions Related to chemistry

Which acids/ bases are used for the following?
(i) To neutralize sting of wasps
(ii) In alkaline batteries
(iii) Manufacturing of soap

chemistry introduction to acid and base neutralisations in everyday life acids and bases in daily life neutralisation reaction

  1. (i) $CH _3CHO$ (ii) $CsOH$ (iii) $Ca(OH) _2$

  2. (i) $CH _3COOH$ (ii) $CuSO _4$ (iii)$ Ba(OH) _2$

  3. (i) $CH _3COOH$ (ii) $KOH$ (iii)$ NaOH$

  4. None of these

Show answer
Correct Option: C
Explanation:
  1. Formic acid is produced by ants and acetic acid is used as anti-wasp agents.
    2. In alkali batteries a base is used as an electrolyte which gives hydroxyl ions in solution.
    3. Manufacturing of soap requires an alkali like $NaOH$ and long chain of fatty acids like sodium stearate to form an ester or sodium acetate salt.

$X+H _2O\rightarrow Y$. 

$Y$ is used to remove grease stains from woollen clothes. Identify $X$ and $Y$.

chemistry introduction to acid and base neutralisations in everyday life acids and bases in daily life neutralisation reaction

  1. $X=HCl,  Y=NaOH$

  2. $X=NH _4OH,  Y=NH _3$

  3. $X=NH _3,  Y=NH _4OH$

  4. None of these

Show answer
Correct Option: C
Explanation:

Ammonia solution is good for removing stains and tarnish and can also repel moths and reduce paint odours. As ammonia reacts with the water, it is dissolved in to produce ammonium ions and hydroxide ions.

Indigestion is painful so to relieve indigestion, we take an antacid such as milk of magnesia , which 
contains :

chemistry introduction to acid and base neutralisations in everyday life acids and bases in daily life neutralisation reaction

  1. magnesium hydroxide

  2. hydrochloric acid

  3. tartaric acid

  4. calcium hydroxide

Show answer
Correct Option: A
Explanation:

Milk of magnesia (also known as magnesium hydroxide; $ { Mg }{ (OH) } _{ 2 } $) is basic in nature and one of the most important ingredients of an antacid. 


The hydroxide ions from $ { Mg }{ (OH) } _{ 2 } $) undergo neutralisation with $ { H }Cl $ in the stomach produced during indigestion or gastric problems, to produce water. Equation is as follows :

$ \quad 2HCl\quad +\quad Mg{ (OH) } _{ 2 }\quad \rightarrow \quad Mg{ (Cl) } _{ 2 }\quad +\quad 2{ H } _{ 2 }O $


Hence the option A is correct.

Ant bite is treated by application of __________.

chemistry introduction to acid and base neutralisations in everyday life acids and bases in daily life neutralisation reaction

  1. washing soda

  2. baking soda

  3. neutral solution

  4. acidic solution

Show answer
Correct Option: B
Explanation:

The venom ant bites are acidic in nature. So, it's effects can be neutralised by bicarbonate of soda such a baking soda or an alkali (basic in nature). 


Hence the correct option is B.

Determine the degree of association (polymerization) for the reaction in aqueous solution
$6HCHO\rightleftharpoons C _6H _{12}O _6$
If observed (mean) molar mass of HCHO and $C _6H _{12}O _6$ is $150$.

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. $0.50$

  2. $0.833$

  3. $0.90$

  4. $0.96$

Show answer
Correct Option: D
Explanation:
Let us consider the problem.
$\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, 6HCHO \,\,\,\,\,\leftrightarrow {C _6}{H _{12}}{O _6}$
At equation $c\left( {1 - \alpha } \right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\dfrac{{C\alpha }}{6}$
$\dfrac{{Observed\,moles\,concentration}}{{Initial\,moles\,concentration}} = \dfrac{{{M _\gamma }}}{{{M _0}}}$
$\dfrac{{C\left( {1 - \alpha } \right) + \dfrac{{C\alpha }}{6}}}{C} = \dfrac{{{M _\gamma }}}{{{M _0}}} = \dfrac{{30}}{{150}}$
Hence the answer is $\alpha  = 0.96$

The monomer that undergo radical polymerisation most easily is ?

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. $CH _2=CH _2$

  2. $C _6H _5CH=CH _2$

  3. $CH _2=C{(Me)} _2$

  4. $CH _3-CH=CH _2$

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Correct Option: A

During the vinyl polymerisation, the chain transfer agent is:

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. $C{Cl} _{4}$

  2. ${C} _{6}{H} _{5}OH$

  3. t-butyl peroxide

  4. diphenylamine

Show answer
Correct Option: A
Explanation:
In the presence of $C{Cl} _{4}$ or any other chain transfer agents, the monomer polymerizes to give lower average molecular mass polymers.
Hence, the correct option is A.

Which one of the following polymer is step-growth polymer

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. Polythylene

  2. Nylon-$66$

  3. Buna-$S$ rubber

  4. Orlon

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Correct Option: A

Which of the following free radicals is the most stable ?

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. primary

  2. methyl

  3. secondary

  4. tertiary

Show answer
Correct Option: D
Explanation:

Electron poor species are stabilized by neighboring atoms that can donate electron density. The most common way to interpret rich neighbors here is the observation that increasing the number of alkyl groups on the carbon bearing the free radical increases its stability. 


Radical stability increases in the order methyl < primary < secondary < tertiary. 

Hence, option $D$ is correct.

Which of the following polymer is not an addition polymer?

chemistry polymer addition polymerisation types of polymerisation reactions petrochemicals and polymers

  1. Teflon

  2. BUNA-N

  3. PAN

  4. Propylene

Show answer
Correct Option: B
Explanation:

BUNA-N is formed by removal of water molecule so it is condensation polymer.