Tag: chemistry

Questions Related to chemistry

During the charging of lead accumulator battery voltage varies from:

chemistry changes - physical and chemical effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $2.15$ V to $1.88$ V

  2. $1.88$ V to $2.0$ V

  3. $1.88$ V to $2.15$ V

  4. does not change

Show answer
Correct Option: C
Explanation:

When the lead accumulator battery is charged, the voltage range is 1.88 V to 2.15 V as the concentration of sulphuric acid varies from 5% to 40%.


Hence, option C is correct.

Calcium hydroxide $\xrightarrow {\Delta}$ Calcium oxide + water. Identify the type of chemical reaction:

chemistry chemical reactions effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. Decomposition Reactions

  2. Neutralization Reactions

  3. Displacement Reactions

  4. Combination Reactions

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Correct Option: A

Balance the reaction of copper sulphide with dilute hydrochloric acid. 

chemistry chemical reactions effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. ${ Cu } _{ 2 }S+2HCl\rightarrow { 2CuCl }+{ H } _{ 2 }S$

  2. ${ Cu } _{ 2 }S+HCl\rightarrow { CuCl }+{ H } _{ 2 }S$

  3. ${ Cu } _{ 2 }S+HCl\rightarrow { CuCl } _{ 2 }+{ H } _{ 2 }+{S}$

  4. $2{ Cu } _{ 2 }S+2HCl\rightarrow 2{ CuCl } _{ 2 }+{ S } _{ 2 }+{H} _{2}S$

Show answer
Correct Option: A
Explanation:

$Cu _2S+2HCl\longrightarrow 2CuCl+H _2S$

No. of Atom | No. of Atom | | --- | --- | --- | | $Cu$ |  $2$ | $2$ | | $S$ | $1$ | $1$ | | $H$ | $2$ | $2$ | | $Cl$ | $2$ | $2$ |

Correct balanced equation from the following reactions is:

chemistry chemical reactions effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $S + 3HNO _3 \rightarrow H _2SO _4 + NO _2 + 3H _2O$

  2. $S + HNO _3 \rightarrow H _2SO _4 + 2NO _2 + H _2O$

  3. $S + 3HNO _3 \rightarrow H _2SO _4 + 6NO _2 + 2H _2O$

  4. $S + 6HNO _3 \rightarrow H _2SO _4 + 6NO _2 + 2H _2O$

Show answer
Correct Option: D
Explanation:

Reaction:
$S + 6HNO _3 \rightarrow H _2SO _4 + 6NO _2 + 2H _2O$

Give a balanced equation for thermal dissociation of a solid [both containing the chloride ion].

chemistry chemical reactions effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. $2{ NH } _{ 4 }Cl\left( s \right) \rightleftharpoons { N _2H _6}\left( g \right) +2HCl\left( g \right) $

  2. ${ NH } _{ 4 }Cl\left( s \right) \rightleftharpoons { NH } _{ 3 }\left( g \right) +Cl _2\left( g \right) $

  3. ${ NH } _{ 4 }Cl\left( s \right) \rightleftharpoons { NH } _{ 3 }\left( g \right) +H _2\left( g \right) $

  4. ${ NH } _{ 4 }Cl\left( s \right) \rightleftharpoons { NH } _{ 3 }\left( g \right) +HCl\left( g \right) $

Show answer
Correct Option: D
Explanation:

On heating ammonium chloride above 340$^0$C it decomposes into mixture of ammonia and hydrochloric gas. It is a reversible reaction.
${ NH } _{ 4 }Cl\left( s \right) \rightleftharpoons { NH } _{ 3 }\left( g \right) +HCl\left( g \right) $

The main cause of rancidity in foods is:

chemistry metals effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. bacteria

  2. proteins

  3. antioxidants

  4. oxidation of the fatty acid molecule

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Correct Option: D
Explanation:

The condition produced by aerial oxidation of fats and oils in food, due to which unpleasant taste and smell occurs is called as rancidity.

The term used to indicate the development of unpleasant smell and taste in fat and oil-containing foods due to aerial oxidation is:

chemistry metals effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. acidity

  2. radioactivity

  3. rabidity

  4. rancidity

Show answer
Correct Option: D
Explanation:

The term used to indicate the development of unpleasant smell and taste in fat and oil containing foods due to aerial oxidation is rancidity.
The process of oxidizing fatty and oily substances is called as rancidity.

The term 'rancidity' represents:

chemistry metals effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. acid rain

  2. oxidation of fatty food

  3. rottening of fruit

  4. fading of coloured clothes in the sun

Show answer
Correct Option: B
Explanation:

Rancidity is a very general term and in its most general meaning, it refers to the spoilage of a food in such a way that it becomes undesirable (and usually unsafe) for consumption.During the process of oxidative rancidity, oxygen molecules interact with the structure of the oil and damage its natural structure in a way that can change its odor, its taste, and its safety for consumption.

Glucose saline is used as:

chemistry metals effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. salt drink

  2. health drink

  3. soft drink

  4. re-hydrating solution

Show answer
Correct Option: D
Explanation:

Glucose is used in oral rehydration therapy as it increases the uptake of water and sodium by the intestines.

Some oils and fats give a bad smell and taste because of  _________ .

chemistry metals effects of oxidation reactions in daily life corrosion of metals electroplating and its application

  1. rancidity

  2. decomposition reaction

  3. hydrogenation reaction

  4. double displacement reaction 

Show answer
Correct Option: A
Explanation:

Rancidity is the oxidation of oils and fats changing their taste and smell. Specifically, it is the hydrolysis and/or auto-oxidation of fats into short-chain aldehydes and ketones which are objectionable in taste and odour.