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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 85101. |
Alcohols ere |
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Answer» WEAKER ACID than water |
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| 85102. |
Activation energy of any reaction depends on |
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Answer» Temperature |
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| 85103. |
Alcohols can be prepared by hydration of, |
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Answer» ALKANES |
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| 85104. |
Activation energy of forward and backward process of a reaction are 60Kjmol^(-1) respectively. Which of the following are true for the reaction? |
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Answer» It is ENDOTHERMIC REACTION |
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| 85105. |
Alcohols can be distinguished from ethers by |
| Answer» Answer :A | |
| 85106. |
Alcohols can be converted to various types ofgasoline (petrol) by shape-selective catalysts |
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Answer» MALTASE |
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| 85107. |
Activation energy of a reaction is: |
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Answer» The ENERGY released during the reaction |
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| 85108. |
Activation energy of a chemical reaction can be determined by…….. |
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Answer» Changing CONCENTRATION of reactants |
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| 85109. |
Activation energy of a chemical reaction can be determined by...... |
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Answer» changing concentration of the reactants |
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| 85110. |
Activation energy of a reactant is reduced by ________. |
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Answer» increased TEMPERATURE |
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| 85111. |
Alcohols are soluble in polar solvents like water due to |
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Answer» INTERMOLECULAR hydogen bonding |
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| 85112. |
Activation energy of a chemical reaction can be determined by …………………… . |
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Answer» determining the RATE constant at standard temperature |
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| 85113. |
Activation energy of a chemical reaction can be determined by |
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Answer» EVALUATING rate constants at two DIFFERENT temperatures |
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| 85114. |
Activation energy of a chemical reaction can be determined by: |
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Answer» evaluating rate constant at standard temeprature. |
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| 85115. |
Alcohols are phenols consist of two parts, an alkyl/aryl group and a hydroxyl group. The properties of alcohols and phenols are chiefly due to the hydroxyl group. The nature of alkyl and aryl groups simply modify these properties. The boiling points of alcuhols and phenols increase with increase in the number of carbun atoms (increase in van der Waals forces). In alcohols, the builing points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surface area). The - OH group in alcohols and phenols is involved in intermolecular hydrogen bonding. It is interesting to note that boiling points of alcohols and phenols are higher in compariscn to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and heloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Arrange methoxymethane, ethanol and propane in increase order of their boiling points. |
| Answer» SOLUTION :`"PROPANE "LT" METHOXYMETHANE "lt" ETHANOL"` | |
| 85116. |
Activation energy of a chemical reaction can be determined by ……… |
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Answer» DETERMINING the RATE CONSTANT at standard temperature If rate constant at `T_(1)` TEMERATURE=`k_(1)` and rate constant at `T(2)` temperature=`k_(2)` |
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| 85117. |
Alcohols are phenols consist of two parts, an alkyl/aryl group and a hydroxyl group. The properties of alcohols and phenols are chiefly due to the hydroxyl group. The nature of alkyl and aryl groups simply modify these properties. The boiling points of alcuhols and phenols increase with increase in the number of carbun atoms (increase in van der Waals forces). In alcohols, the builing points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surface area). The - OH group in alcohols and phenols is involved in intermolecular hydrogen bonding. It is interesting to note that boiling points of alcohols and phenols are higher in compariscn to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and heloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Why do branched alcohols show a smaller boiling points than straight chain alcohols ? |
| Answer» Solution :Branched MOLECULES have smaller area of CONTACT and smaller van der Waals FORCES of attraction and HENCE smaller BOILING points. | |
| 85118. |
Activation energy of a chemical reaction can be determined by ……………. . |
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Answer» changing CONCENTRATION of the REACTANTS |
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| 85119. |
Activation energy is equal to __________ |
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Answer» THRESHOLD ENERGY + Energy of colloding MOLECULES |
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| 85120. |
Alcohols are phenols consist of two parts, an alkyl/aryl group and a hydroxyl group. The properties of alcohols and phenols are chiefly due to the hydroxyl group. The nature of alkyl and aryl groups simply modify these properties. The boiling points of alcuhols and phenols increase with increase in the number of carbun atoms (increase in van der Waals forces). In alcohols, the builing points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surface area). The - OH group in alcohols and phenols is involved in intermolecular hydrogen bonding. It is interesting to note that boiling points of alcohols and phenols are higher in compariscn to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and heloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Which kind of hydrogen bonding is involved in alcohols ? |
| Answer» SOLUTION :INTERMOLECULAR HYDROGEN BONDING. | |
| 85121. |
Activation energy for the acied catalysed hydrolysis of sucrose is 6.22 KJ mol ^(-1), while the activation energy is only 2.15 KJ mol^(-1) when hydrolysis is catalysed by the enzyme sucrose. Explain. |
| Answer» Solution :Enzymes are biocatalysts. They reudce the MAGNITUDE of activation energy by providing ALTERNATIVE path. For example, in the hydrolysis of sucrose , the enzyme sucrase reduces the activation energy from `6.22 kj mol^(-1)` to `2.15kj mol^(-1)`. As a result , enzyme catalysed REACTIONS occur at a MUCH faster rate than the ordinary LABORATORY chemical reactions using conventional catalysts. | |
| 85122. |
Activation energy is |
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Answer» The amount of energy to be ADDED to the ACTUAL energy of a molecule so that the threshold energy is reached |
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| 85123. |
Activation energy is low for fast reactions. Explain. |
| Answer» SOLUTION :In the FAST reaction more NUMBER of molecules ,easily cross over the ENERGY barrier (threshold energy barrier)to from the product.Since a fast reaction has less threshold energy (E_th0 ,the activation energy (E_a) is low as compared to slow reaction as E_r=E-th-E_t.where E_t is the energy of reactant. | |
| 85124. |
Alcohols are phenols consist of two parts, an alkyl/aryl group and a hydroxyl group. The properties of alcohols and phenols are chiefly due to the hydroxyl group. The nature of alkyl and aryl groups simply modify these properties. The boiling points of alcuhols and phenols increase with increase in the number of carbun atoms (increase in van der Waals forces). In alcohols, the builing points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surface area). The - OH group in alcohols and phenols is involved in intermolecular hydrogen bonding. It is interesting to note that boiling points of alcohols and phenols are higher in compariscn to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and heloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Out of ethanol and propan-1-ol, which has the higher boiling point ? |
| Answer» SOLUTION :Propan-1-ol has the HIGHER bciling POINT. | |
| 85125. |
Activation energy for the acid catalysed hydrolysis of sucroseis6.22 kJ mol^(-1) , whilethie activation energy is only 2.15kJ mol^(-1) whenhydrolysisis catalysedby theenzymesucrase. |
| Answer» Solution :ENZYME act as catalysts and reduce themagnitudeof ACTIVATION energyby providingalternativepath. In the hydrolysis ofsurcosethe enzyme sucrase REDUCES theactivation energy from`6.22 kJ MOL^(-1) ` to `2.15 kJ mol^(-1)` | |
| 85126. |
Activation energy (E_(a)) and rate constants (K_(1) and K_(2)) of a chemical reaction at two different temperatures (T_(1) and T_(2) ) are related by |
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Answer» LN `(K_(2))/(K_(1)) = - (E_(a))/ ( R) ((1)/(T_(1)) - (1)/(T_(2)))` ln `(K_(2))/(K_(1)) = (E_(a))/(R) ((1)/(T_(1)) - (1)/(T_(2)))` ln `(K_(2))/(K_(1)) = - (E_(a))/(R) ((1)/(T_(2)) - (1)/(T_(1)))` |
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| 85127. |
Alcohols are phenols consist of two parts, an alkyl/aryl group and a hydroxyl group. The properties of alcohols and phenols are chiefly due to the hydroxyl group. The nature of alkyl and aryl groups simply modify these properties. The boiling points of alcuhols and phenols increase with increase in the number of carbun atoms (increase in van der Waals forces). In alcohols, the builing points decrease with increase of branching in carbon chain (because of decrease in van der Waals forces with decrease in surface area). The - OH group in alcohols and phenols is involved in intermolecular hydrogen bonding. It is interesting to note that boiling points of alcohols and phenols are higher in compariscn to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and heloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methoxymethane is intermediate of the two boiling points. The high boiling points of alcohols are mainly due to the presence of intermolecular hydrogen bonding in them which is lacking in ethers and hydrocarbons. Which part in alcohols and phenols mainly determines their properties ? |
| Answer» Solution :It is the `-OH` group in alcohols and PHENOLS which determines the PROPERTIES of these COMPOUNDS. | |
| 85128. |
Activation energy for the acid catalysed hydration of sucrose is 6.22 kJ mol^(-1), while the activation energy is only 2.15 kJ mol^(-1) when hydrolysis is catalysed by the enzyme sucrase. Explain. |
| Answer» Solution :ENZYMES are needed only in small quantities for the progress of reaction. Similar, to the action of chemical catalyst, enzymes are SAID to reduce the MAGNITUDE of activation energy. For example, the activation energy for acid hydrolysis of sucrose is `6.22 KJ mol^(-1)`, while the activation energy is only `2.15 kJ mol^(-1)` when hydrolysed by the enzyme sucrase. | |
| 85129. |
Alcohols are obtained by reduction of 1. R-CHO ,2. R-COR, 3 · R-COOH ,4. RCOOR |
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Answer» 1, 3 |
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| 85130. |
Activation energy (E_(a)) and rate constants (k_(1) "and" k_(2)) of a chemical reaction at two different temperatures (T_(1) "and" T_(2)) are realted by |
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Answer» `1n(k_(2))/(k_(1))=-(E_(0))/(R)((1)/(T_(1))-(1)/(T_(2)))` |
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| 85131. |
Activation energy (E_(a)) and rate constant (k_(1) and k_(2)) of chemical reaction at two different temperatures (T_(1) and T_(2)) are related by : |
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Answer» `In(k_(2))/(k_(1))=(E_(a))/(R)[(1)/(T_(1))-(1)/(T_(2))]` `In(k_(1))/(k_(2))=-(E_(a))/(R)[(1)/(T_(1))-(1)/(T_(2))]` |
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| 85132. |
Alcohols are neutral in character whereas thio-aicohols are______ in character. |
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Answer» STRONGLY acid |
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| 85133. |
Activation energy (E_(a)) and rate constant (K_(1) and (K_(2)) for a chemical reaction at two different temperatures T_(1) and T_(2) are related by: |
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Answer» In `K_(2)/K_(1) = E_(a)/R(1/T_(1) - 1/T_(2))` |
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| 85134. |
Alcohols are miscible with H_2O because of their |
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Answer» ACIDIC character |
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| 85135. |
Alcohols are comparatively more soluble in water than hydrocarbons of comparables molecular masses.Explain this fact. |
Answer» Solution :Alcohol can FORM HYDROGEN bonds with water and break the hydrogen bonds existing between water molecules. HENCE they are SOLUBLE in water.  On the other HAND, hydrocarbons cannot form hydrogen bonds with water molecules and hence are insoluble in water. |
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| 85136. |
Activation energy depends on |
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Answer» pressure |
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| 85137. |
Activationenergies for different reactions are give below a. Ato products Ea=14K.Cal b. Bto products, Ea=15K.cal c. Cto products, Ea=1K.Cal d. Dto products, Ea=10K.cal IF the temperature increases by 10^(@)C for which reactions the temperature coefficients ((k_(1)+10)/(k_(1))) are maximum and minimum respectively. |
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Answer» a & b |
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| 85138. |
Activation energies for different reactions are given below (a) A to products, Ea=14 K.Cal (b)B to products, Ea=16 K.cal (c)C to products, Ea=12 K.Cal (d)D to products, Ea=10 K.cal If the temperature increases by 10^(0)C for which reactions the temperature coefficients are maximum and minimum respectively. |
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Answer» a & b |
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| 85139. |
Alcohols are acidic in nature because hydrogen is attached to oxygen which is an electronegative element. Alcohol is weaker acidthan water because OH^(-)ion is more stable than R-O^(-) ion. R-O^(-)is less stable, due to +I effect of the alkyl group. Acidity of alcohols increases with increase in the stability of acid anion. Some alcohol like CH_(3)-OH, CF_(3)-CH_(2)-OH, (CF_(3))_(3)C-OHae more acidic than water. Which of the following will react fastest with sodium ? |
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Answer»
Keto group INCREASES the acidic character hence,  will react FASTEST with sodium .
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| 85140. |
Activated charcoal is used to remove colouring matter from pure substances. It works by |
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Answer» oxidation |
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| 85141. |
Alcohols are comparatively more soluble in water than hydrocarbons of comparable molecular masses. Explain this fact. |
Answer» Solution :Alcohols can formm H-bonds with water and can also BREAK the H-bonds already existing between water molecules. Therefore, they are soluble in water.  On the other HAND, hydrocarbons can NEITHER form H-bonds with water nor ca break the H-bonds already existing between water molecules and HENCE are INSOLUBLE in water. |
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| 85142. |
Alcohols are |
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Answer» neutral |
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| 85143. |
Alcohols are …. |
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Answer» BRONSTED Base |
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| 85144. |
Alcohols are __________ |
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Answer» WEAKER acid than water |
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| 85145. |
Alcoholicsolution of KOH is used for , |
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Answer» Dehydration In alcoholic KOH alkoxide ions `(RO^-)` are present which is a strong base. They abstract proton from `beta`-carbon of alkyl halide and FAVOURS elimination REACTION. `underset"Alcohol""ROH"+KOHto underset"Potassium alkoxide"(ROK+H_2O)` `ROK to underset"Alkoxide ion"(RO^-) + K^+` `RO^(-) + H -oversetbeta(CH_2)-oversetalpha(CH_2)-Br to ROH + CH_2 =CH_2 +KBr` |
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| 85146. |
Actione of HNO_2 onCH_3NH_2 gives : |
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Answer» `CH_3OH` |
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| 85147. |
Alcoholic solution of KOH is used for |
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Answer» Dehydrogenation |
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| 85148. |
Action of water in the presence of sulphuric acid with the following alkenes (i) (ii) CH_(3)-CH=H_(2) gives |
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Answer» (i) 
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| 85149. |
Action of water or dilutemineral acidson metals can give |
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Answer» monohydrogemn |
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| 85150. |
Action of soap is due to emulsification and micelle formation. Explain |
| Answer» | |
