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Materials we use - class-X

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Match the column I with column II and mark the appropriate choice.

Column I Column II
(A) $CH _3(CH _2) _{10}CH _2OS{ O }^- _3Na^+$ (i) Cationic detergent
(B) $[CH _3(CH _2) _{15}N(CH _3) _2-CH _3]^+Br^-$ (ii) Non-ionic detergent
(C) $CH _3(CH _2) _{16}COO(CH _2CH _2O) _nCH _2CH _2OH$ (iii) Soap
(D) $C _{17}H _{35}COONa$ (iv) Anionic detergent
  1. (A) $\rightarrow$(iii), (B) $\rightarrow$(ii), (C) $\rightarrow$(iv), (D) $\rightarrow$(i)

  2. (A) $\rightarrow$(ii), (B) $\rightarrow$(iv), (C) $\rightarrow$(i), (D) $\rightarrow$(iii)

  3. (A) $\rightarrow$(i), (B) $\rightarrow$(iii), (C) $\rightarrow$(iv), (D) $\rightarrow$(ii)

  4. (A) $\rightarrow$(iv), (B) $\rightarrow$(i), (C) $\rightarrow$(ii), (D) $\rightarrow$(iii)


Correct Option: D
Explanation:
  • Anionic detergents are sodium salts of sulphonated long chain alcohols or hydrocarbons. Alkyl hydrogensulphates formed by treating long chain alcohols with concentrated sulphuric acid are neutralised with alkali to form anionic detergents.
  • Here, option A which is $CH _3(CH _2) _{10}CH _2OSO^{-} _{3}Na^{+}$ Sodium laurylsulphate is an Anionic detergent.
  • Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions. Cationic part possess a long hydrocarbon chain and a positive charge on nitrogen atom. Hence, these are called cationic detergents.
  • Here,option B wich is $[CH _3(CH _2) _{15}N(CH _3) _2-CH _3]^{+}Br^{-}$ is a Cationic detergent.
  • Non-ionic detergents do not contain any ion in their constitution. One such detergent is formed when stearic acid reacts with polyethyleneglycol.
  • Here option C which is $CH _3(CH _2) _{16}COO(CH _2CH _2O) _nCH _2CH _2OH$ is a Non-ionic detergent.
  • Soaps are the sodium salts of long chain carboxylic acids. Here option D which is $C _{17}H _{35}COONa$ is a soap.

Glycerol is added to soap. It functions :

  1. as a filler

  2. to increase lathering

  3. to prevent rapid drying

  4. to make soap granules


Correct Option: C
Explanation:

Cleansing action of Soaps and detergents-
  • Most of the dirt is oily in nature and oil does not dissolve in water. The molecule of soap constitutes sodium or potassium salts of long chain carboxylic acids. In the case of soaps, the carbon chain dissolves in oil and the ionic end dissolves in water.
  • Glycerol is a humectant - a substance that attracts water.
  • It has the ability to draw in moisture preventing drying of the skin.
  • Hence, Glycerol is added to soap to prevent rapid drying.

What happens when a detergent is added to water?

  1. Surface tension increases.

  2. Surface tension decreases.

  3. Viscosity increases.

  4. Viscosity decreases.


Correct Option: B,C
Explanation:

When detergent is added to water, the detergent molecules break down the cohesive attractive forces of the water molecules at the surface. Thus, the surface tension is broken and viscosity increases due to attractive forces between water molecules and detergents.

Which phenomenon is/are observed during washing of clothes by detergents?

  1. Micelle formation

  2. Adsorption

  3. Emulsification

  4. Foaming


Correct Option: A,B,C,D
Explanation:

Micelle is an aggregate of surfactant molecules dispersed in a liquid colloid. A typical micelle in aqueous solution  forms an aggregate with the hydrophilic  "head" regions in contact with surrounding solvent. 
Adsorption is the adhesion of atoms, ions or molecules from a gas, liquid, or dissolved solid to a surface.
Emulsification is the process of making emulsions. Emulsions are made by shaking the dispersed phase and dispersion medium vigorously and then stabilizing the emulsion with an emulsifier. Most often soaps and detergents are added to stabilize emulsions. Stabilization is obtained by the coating of the drops of an emulsion by the stabilizer. This prevents the drops of the emulsion from combining together and separating out as a separate layer.
Foaming is the volume is expansion using air bubbles. This enables a rather lightweight material to be created even when it occupies a large volume. Also, the air layer adds heat-insulating and shock-absorbing (cushioning) properties. This happens when we apply soap while washing our clothes.
So, all phenomenon are observed during washing of cloth by detergents.
Hence, options A,B,C and D, all are correct options.

The antiseptic action of dettol is due to:

  1. Chloro benzene

  2. Chloroxylenol

  3. Chloroquine

  4. Chloramphenicol


Correct Option: B
Explanation:

The antiseptic action of dettol is due to Chloroxylenol. It also shows moderate antibacterial effects.

Why is soap referred as a salt?

  1. They are long chain of fatty acids

  2. Made up of various salts

  3. Gives salt on acting with water

  4. None of above


Correct Option: A
Explanation:

Many soaps are simply neutralized, long chain carboxylic and/or fatty acids. Usually neutralized by some mineral base. The neutralization reaction of an acid and a base produces a salt.

Which of the following is a type of soap?

  1. Hard soap

  2. Soft soap

  3. Both $A$ and $B$

  4. None of above


Correct Option: C
Explanation:

Depending upon the nature of alkali used in the production of soap, they are classified into two types.
The sodium salt of long chain fatty acid is known as hard soap.
The potassium salt of long chain fatty acid is known as soft soap, as it produces more lather.

What is salting out of soap?

  1. Formation of salt

  2. Formation of acids in aqueous medium

  3. Melting if soap

  4. Precipitation of soap in solid form


Correct Option: D
Explanation:

The saponification  reaction is exothermic in nature, because heat is liberated during the process. The soap formed remains in suspension form in the mixture. Soap is precipitated as a solid from the suspension by adding common salt to the suspension. This process is called salting out of Soap.

Process that produces soap from fats is called as:

  1. acidification

  2. saponification

  3. hydrolysis

  4. condensation


Correct Option: B
Explanation:

Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fat/oil react with aqueous $NaOH$ or $KOH$, they are converted into soap and glycerol. This is called alkaline hydrolysis of esters. Since this reaction leads to the formation of soap, it is called the Saponification process.

_________ is used as laundry soap.

  1. Hard soap

  2. Soft soap

  3. Both $A$ and $B$

  4. None of above


Correct Option: A
Explanation:

The sodium salt of long chain fatty acid is known as hard soap. It is difficult to dissolve in water. It is used as laundry soap.

When $NaOH$ is used in making of soap, it is called as:

  1. alkali soap

  2. soft soap

  3. hard soap

  4. none of above


Correct Option: C
Explanation:

Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fat/oil react with aqueous $NaOH$ or $KOH$, they are converted into soap and glycerol.  The sodium salt of long chain fatty acid is known as hard soap. It is difficult to dissolve in water. It is used as laundry soap.

Assertion: Hard water consumes more soap.
Reason: The ion responsible for cleansing action is precipitated out by $Ca^{2+}$ or $Mg^{2+}$ ion.

  1. Assertion is correct but Reason is wrong.

  2. Assertion is correct but Reason is right.

  3. Both Assertion and Reason are correct and Reason is the correct explanation of Assertion.

  4. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion.


Correct Option: C
Explanation:

Hard water consumes more soap because hard water contains dissolved salts of calcium, magnesium and other heavy metals and it does not form lather with soap readily, due to the reaction shown below.

$2RCOONa + Ca^{2+}  \rightarrow (RCOO) _2 Ca + 2 Na^+$

Soaps are formed by saponification of?

  1. alcohols

  2. glycosides

  3. simple esters

  4. carboxylic acids


Correct Option: C
Explanation:

Saponification is formation of soaps from triglycerides (esters) when reacted with sodium hydroxide to give sodium salts of fatty acids.

$\underbrace {C _2H _5COOCH _3} _{Esters}+NaOH\longrightarrow C _2H _5CO\overset {\circleddash}{O}Na+C _2H _3OH$

Which of the following pairs of ions makes the water hard?

  1. $Na^+$

  2. $Cs^+$

  3. $Rb^+$

  4. $Ba^{+2}$


Correct Option: A
Explanation:

Ion-exchange resin can soften both temporary and permanent hard water. The ion-exchange resin starts with sodium ions struck to it. As the bond water passes through the column, sodium ions come off the resin and go into the water.

Thus, ${ Na }^{ + }$ ions makes the water hard.

Soaps cannot be used in hard water because they:

  1. contain sodium

  2. form precipitates

  3. create environmental problems

  4. create ozone depletion


Correct Option: B
Explanation:

Soaps cannot be used in hard water because they forms precipitates. When soaps are used in hard water that contains a lot of calcium and magnesium ions they cause the soap to precipitate and it is unable to form lather. This can be minimized by the addition of chemicals like sodium trimetaphosphate, borax, sodium silicate etc. These prevent the calcium and magnesium ions from reacting with the soap and allow it to form lather, thus forming precipitates.

_________ is a major component of shampoos and soaps 

  1. $Li$

  2. $Na$

  3. $K$

  4. $Fr$


Correct Option: B,C

Which of the following statement is not correct ? 

  1. KCI is a substitute for NaCI for patients of high blood pressure.

  2. KOH is a stronger alkali than NaOH

  3. KOH is used in the manufacture of soft soap.

  4. NaOH is a non-deliquescent white crystalline solid.


Correct Option: C

Assertion : In O/W emulsion, soap is mixed
Reason : Soap reduces surface tension

  1. If both assertion and reason are true and reason is the correct explanation of assertion.

  2. If both assertion and reason are true but reason is not the correct explanation of assertion.

  3. If assertion is true but reason is false.

  4. If both assertion and reason are false.


Correct Option: A
Explanation:

For emulsification soap is added in O/W emulsion as it reduces surface tension and form better colloid.

Fertilisers are used to provide three elements needed to increase the yield of crops.
Which two compounds would provide all three of these elements?

  1. ammonium nitrate and calcium phosphate

  2. ammonium nitrate and potassium sulfate

  3. potassium nitrate and calcium phosphate

  4. potassium nitrate and potassium sulfate


Correct Option: C
Explanation:

$\text{All fertilizer labels have three bold numbers. The first number is the }$$\text{the second number is the amount of phosphate and the third number is the amount of potas. }$$\text{These three numbers represent the primary nurtients (nitrogen(N)-phosphorus(P)-potassium(K)).}$

Household detergent cause water pollution.

  1. True

  2. False


Correct Option: A
Explanation:

Household detergents do cause water pollution.

Statement: Detergents give scum with hard water.


State whether the given statement is true or false.

  1. True

  2. False


Correct Option: B
Explanation:

Detergents are not soaps. Detergents work by coming in contact with a surface and reducing surface tension, with something known as a surfactant. Basically allowing the dirt to slide away. Detergents are synthetics. Soap is natural, like glycerine or tallow.But they are very active in hard water.
One reason why laundry detergents work better than soap is that they contain substances that soften the water. Hard water contains dissolved calcium $Ca^{+2}$ and magnesium $Mg^{+2}$ ions. These ions interfere with the action of soap by reacting with it to form a gray, slimy substance called curd or soap scum. Laundry detergents inhibit curd formation because they contain substances such as sodium carbonate $(NaCO _{3})$ that removes the Ca and Mg ions from the water. When sodium carbonate dissolves in water it separates to form Na ions and $CO _{3}$ ions. The dissolved $CO _{3}$ ions react with the Ca and Mg to form $CaCO _{3}$ and $MgCO _{3}$ which are solids and settle to the bottom of the washer. Hence given statement is false because it given scum even in soft water but not that much.

Soaps are water soluble while detergents are water insoluble.

  1. True

  2. False


Correct Option: B
Explanation:

Soaps are water-soluble sodium or potassium salts of fatty acids. Soaps are made from fats and oils, or their fatty acids, by treating them chemically with a strong alkali.
detergent is a surfactant, usually alkylbenzenesulfonates , a family of compounds that are similar to soap but are more soluble in hard water, because the polar sulfonate (of detergents) is less likely than the polar carboxyl (of soap) to bind to calcium and other ions found in hard water.Option B is correct.

What change will you observe if you test soap with litmus paper (red and blue)?

  1. It will turn red litmus blue

  2. It will turn blue to red

  3. Red litmus paper won't change colour

  4. None of these


Correct Option: A
Explanation:

Since, soaps are basic in nature, thus, it turns red litmus paper to blue. When blue litmus paper is dipped in soap solution, it remains blue.


Option A is correct.

Micelle formation take place when soap is added to water? Will a micelle be formed in other solvents like ethanol also?

  1. True

  2. False


Correct Option: B
Explanation:

A molecule of soap has two dissimilar ends. At one end is the hydrocarbon chain which is water repellent. At the other end carboxylate anion is present which is water soluble end. When soap is dissolved in water, many molecules come together and form a group called micelle, these micelles are formed because their hydrocarbon chains come together and the polar ends are projected outward. Micelle formation in ethanol will not occur because the hydrocarbon chain end of the soap will also dissolve in water.

Washing powders contain detergents in the range of (by mass):

  1. $10-15\%$

  2. $15-30\%$

  3. $50-60\%$

  4. $40-50\%$


Correct Option: B
Explanation:

Modern synthetic detergents are alkyl or aryl sulphonates produced from petroleum (or coal) and sulphuric acid. They can be defined as the sodium or potassium salt of a long chain alkyl benzene sulphonic acid or the sodium or potassium salt of a long chain alkyl hydrogen sulphate, that has cleansing properties in water.
They are used in washing powders in a proportion of about $15-30\%$.

Which of the following substance has bitter taste?

  1. Milk

  2. Amla

  3. Soap solution

  4. Salt solution


Correct Option: C
Explanation:

Soaps are obtained by treating vegetable or animal oils and fats with a strong alkaline solution. Basic solutions are bitter in taste.

Soaps are sodium salts of :

  1. mineral acids

  2. fatty acids

  3. bases

  4. carbonic acid


Correct Option: B
Explanation:

Soap is a salt of fatty acid. These are obtained by treating vegetable or animal oils and fats with strong alkaline solution. Fats and oils are composed of triglycerides,three molecules of fatty acids are attached to a single molecule of glycerol. This alkaline solution often called as lye brings about a chemical reaction known as saponification.

A detergent is :

  1. cleaning agent

  2. drugs

  3. soap

  4. catalyst


Correct Option: A
Explanation:

A detergent is a cleaning agent.

Soaps are:

  1. sodium or potassium salts of higher fatty acid

  2. esters of higher fatty acids

  3. glycerides of fatty acids

  4. hydrides of fatty acids


Correct Option: A
Explanation:
Soaps are water-soluble sodium or potassium salts of fatty acids. Soaps are made from fats and oils, or their fatty acids, by treating them chemically with a strong alkali. 
$C _{12}H _{35}COONa$ is a good example of soap. 

Hence, option $A$ is correct.

Sodium hydroxide is found in:

  1. lime water

  2. milk of magnesia

  3. window cleaner

  4. soap


Correct Option: D
Explanation:

$\bullet$ Lime water has $Ca(OH) _2$

$\bullet$ Milk of magnesia has $Mg(OH) _2$
$\bullet$ Window cleaner has $NH _4OH$
$\bullet$ Soap consists of sodium stearate and $NaOH$.

A product obtained by mixing caustic soda with vegetable oils is:

  1. acid

  2. base

  3. soap

  4. vinegar


Correct Option: C
Explanation:

When vegetable oils reacted with caustic soda they produce potassium salt of Carboxylate. (Soap)

$\implies Vegetable\ oil+KOH\longrightarrow \underbrace {R-CO\overset {\circleddash}{O}K} _{soap}$

We can use soap to check the hardness of water.

  1. True

  2. False


Correct Option: A
Explanation:

Soap get precipitated in hard water, but not in soft water.Therefore soaps can be used to check the hardness of water.

Which type of chemical substances is disparlure?

  1. Detergent

  2. Antioxidant

  3. Pheromones

  4. Preservative


Correct Option: C
Explanation:

Disparlure is a pheromones that attracts insects. Pheromones are an additional form of chemical communication that occurs between rather than within individuals.

The soap molecule has a :

  1. hydrophilic head and a hydrophobic tail

  2. hydrophobic head and a hydrophilic tail

  3. hydrophobic head and a hydrophobic tail

  4. hydrophilic head and a hydrophilic tail


Correct Option: A
Explanation:
The basic structure of all soaps is essentially the same, consisting of a long hydrophobic (water-fearing) hydrocarbon chain tail and a hydrophilic (water-loving) anionic head.

Hence the correct option is A.

Washing soaps produce scum with hard water and not much foam because hard water contains:

  1. chalk and sulphur

  2. many dissolved inorganic salts

  3. many suspended particles

  4. organic matter


Correct Option: B
Explanation:

Hard water contains salts of calcium and magnesium principally as bicarbonates, chlorides, and sulfates. Ferrous ion may also be present; oxidized to the ferric form. It appears as a reddish brown stain on washed fabrics and enameled surfaces. Water hardness that is caused by calcium bicarbonates is known as temporary, because boiling converts the bicarbonates to the insoluble carbonates; hardness from other salts is called permanent. Calcium and magnesium ions in hard water react with the higher fatty acids off soap to form an insoluble gelatinous curd, thereby causing a waste of the soap.

Face powders are used for a smooth appearance of the skin by covering any unwanted secretions of oil. Which is the main ingredient of face powder?

  1. Precipitates

  2. Talc

  3. Zinc oxide

  4. Zinc stearate


Correct Option: B
Explanation:

Talc is often considered to be the main ingredient of face powder. Talc also known as French chalk, is a naturally occurring minerals that absorbs moisture and oil. It leaves the skin feeling soft and fresh and can help to control shine.

Ordinary gasoline (petrol) that is used as fuel cars, scooters and automobiles contain many different chemicals that are added in small quantities, each performing an important role. Some of these are mentioned here. Which of the option is false?

  1. Soaps used for removing particles of grease from petrol tanks ensure a free flow of petrol

  2. Anti-icing agents are used for depressing the freezing point of particles of ice

  3. Anti-rust agents are used for protecting against corrosion by water

  4. Detergents are used for preventing gums from sticking on the walls of the carbureter


Correct Option: A
Explanation:

$\bullet$ Anti- rust agents are used for protecting iron materials against corrosion by water. Example- Redoxide.

$\bullet$ Anti-icing agents are used for depressing the freezing point of particles of ice.
$\bullet$ Soaps only grease particles from clothes, but it can't remove grease from petrol.

Soaps are sodium salts of fatty acids, RCOONa; e.g. $C _{17}H _{35}COO^-Na^+$. It gives an insoluble precipitate / layer with 

  1. $Ca^{2+}$ (aq)

  2. $Mg^{2+}$ (aq)

  3. HCl (aq)

  4. All of these


Correct Option: D
Explanation:
Soaps are sodium salts of fatty acids. It gives an insoluble precipitate/layer with Calcium, Magnesium ions. It also gives an insoluble layer with HCl acid.

As a cleaning agent, soap suffers from two main drawbacks:

  • It does not function well in acidic solutions because of the formation of insoluble fatty acid 
eg, $CH _3(CH _2) _{16}COO^-Na^+(aq) + HCl(aq) \rightarrow CH _3(CH _2) _{16}COOH(s) + Na^+(aq) + Cl^-(aq)$
  • It forms insoluble precipitates with $Ca^{2+}$ and$ Mg^{2+}$ ions present in hard water, forming a scum 
eg, $2CH _3(CH _2) _{16}COO^-Na^+(aq) + Ca^{2+}(aq) \rightarrow [CH _3(CH _2) _{16}COO^-] _2Ca^{2+}(s) + 2Na^+(aq)$


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