317891
A sample of \({\text{4}}{\text{.50}}\,\,{\text{mg}}\) of unknown alcohol is added to \(\mathrm{CH}_{3} \mathrm{MgBr}\) when \(1.68 \mathrm{~L}\) of \(\mathrm{CH}_{4}\) at STP is obtained. The unknown alcohol is
1 Methanol
2 Ethanol
3 1-Propanol
4 1-Butanol
Explanation:
All the four options given are monohydric alcohols. When a monohydric alcohol is treated with \(\mathrm{CH}_{3} \mathrm{MgBr}\), the number of moles of \(\mathrm{CH}_{4}\) gas produced is a equal to the number of moles of alcohol If \(\mathrm{M}\) is the molecular weight of alcohol, then \(\dfrac{4.50}{\mathrm{M}}=\dfrac{1.68}{22.4}\) On solving, \({\text{M = 60}}\). Therefore, the unknown alcohol is Propan-1-ol.
CHXI13:HYDROCARBONS
317892
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
1 \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\)
2 \(\mathrm{CH}_{4}\)
3 \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\)
4 \(\mathrm{CH} \equiv \mathrm{CH}\)
Explanation:
\({\text{(1) C}}{{\text{H}}_4}{\text{ + B}}{{\text{r}}_{\text{2}}}{\text{ }} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - Br + 2HBr}}\) \({\text{(2) 2C}}{{\text{H}}_{\text{3}}}{\text{ - Br + }}\mathop {{\text{2Na}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - }}\mathop {{\text{C}}{{\text{H}}_{\text{3}}}{\text{ + 2NaBr}}}\limits_{{\text{(}}\,{\text{Less}}\,\,{\text{than}}\,\,{\text{four}}\,\,{\text{carbon)}}} }\limits_{} \) Option I will give hydrocarbon having four carbon atoms .Option 3 and 4 will undergoes addition reaction with \({\text{B}}{{\text{r}}_{\text{2}}}\)
NEET - 2018
CHXI13:HYDROCARBONS
317893
Assertion : Saturated hydrocarbons are chemically less reactive. Reason : All isomeric paraffins have same parent name.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Less reactivity of saturated hydrocarbons is due to presence of single bonds between carbon atoms. Paraffins (alkanes) may have straight chain or branched chain isomers which have different parent names. So, option (3) is correct.
CHXI13:HYDROCARBONS
317894
Select the incorrect statement.
1 Petroleum and natural gas are the main sources of alkanes.
2 Chloroethane on reduction with zinc and dil. HCl produces ethane.
3 In Wurtz reaction, the dry ethereal (free from moisture) solution is used as solvent.
4 Methane can be prepared by Kolbe's electrolysis in good yield.
Explanation:
Methane cannot be prepared by Kolbe's electrolysis because this method is suitable for preparation of symmetrical alkanes i.e., alkanes containing even number of carbon atoms. So, incorrect statement is (4).
317891
A sample of \({\text{4}}{\text{.50}}\,\,{\text{mg}}\) of unknown alcohol is added to \(\mathrm{CH}_{3} \mathrm{MgBr}\) when \(1.68 \mathrm{~L}\) of \(\mathrm{CH}_{4}\) at STP is obtained. The unknown alcohol is
1 Methanol
2 Ethanol
3 1-Propanol
4 1-Butanol
Explanation:
All the four options given are monohydric alcohols. When a monohydric alcohol is treated with \(\mathrm{CH}_{3} \mathrm{MgBr}\), the number of moles of \(\mathrm{CH}_{4}\) gas produced is a equal to the number of moles of alcohol If \(\mathrm{M}\) is the molecular weight of alcohol, then \(\dfrac{4.50}{\mathrm{M}}=\dfrac{1.68}{22.4}\) On solving, \({\text{M = 60}}\). Therefore, the unknown alcohol is Propan-1-ol.
CHXI13:HYDROCARBONS
317892
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
1 \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\)
2 \(\mathrm{CH}_{4}\)
3 \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\)
4 \(\mathrm{CH} \equiv \mathrm{CH}\)
Explanation:
\({\text{(1) C}}{{\text{H}}_4}{\text{ + B}}{{\text{r}}_{\text{2}}}{\text{ }} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - Br + 2HBr}}\) \({\text{(2) 2C}}{{\text{H}}_{\text{3}}}{\text{ - Br + }}\mathop {{\text{2Na}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - }}\mathop {{\text{C}}{{\text{H}}_{\text{3}}}{\text{ + 2NaBr}}}\limits_{{\text{(}}\,{\text{Less}}\,\,{\text{than}}\,\,{\text{four}}\,\,{\text{carbon)}}} }\limits_{} \) Option I will give hydrocarbon having four carbon atoms .Option 3 and 4 will undergoes addition reaction with \({\text{B}}{{\text{r}}_{\text{2}}}\)
NEET - 2018
CHXI13:HYDROCARBONS
317893
Assertion : Saturated hydrocarbons are chemically less reactive. Reason : All isomeric paraffins have same parent name.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Less reactivity of saturated hydrocarbons is due to presence of single bonds between carbon atoms. Paraffins (alkanes) may have straight chain or branched chain isomers which have different parent names. So, option (3) is correct.
CHXI13:HYDROCARBONS
317894
Select the incorrect statement.
1 Petroleum and natural gas are the main sources of alkanes.
2 Chloroethane on reduction with zinc and dil. HCl produces ethane.
3 In Wurtz reaction, the dry ethereal (free from moisture) solution is used as solvent.
4 Methane can be prepared by Kolbe's electrolysis in good yield.
Explanation:
Methane cannot be prepared by Kolbe's electrolysis because this method is suitable for preparation of symmetrical alkanes i.e., alkanes containing even number of carbon atoms. So, incorrect statement is (4).
NEET Test Series from KOTA - 10 Papers In MS WORD
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CHXI13:HYDROCARBONS
317891
A sample of \({\text{4}}{\text{.50}}\,\,{\text{mg}}\) of unknown alcohol is added to \(\mathrm{CH}_{3} \mathrm{MgBr}\) when \(1.68 \mathrm{~L}\) of \(\mathrm{CH}_{4}\) at STP is obtained. The unknown alcohol is
1 Methanol
2 Ethanol
3 1-Propanol
4 1-Butanol
Explanation:
All the four options given are monohydric alcohols. When a monohydric alcohol is treated with \(\mathrm{CH}_{3} \mathrm{MgBr}\), the number of moles of \(\mathrm{CH}_{4}\) gas produced is a equal to the number of moles of alcohol If \(\mathrm{M}\) is the molecular weight of alcohol, then \(\dfrac{4.50}{\mathrm{M}}=\dfrac{1.68}{22.4}\) On solving, \({\text{M = 60}}\). Therefore, the unknown alcohol is Propan-1-ol.
CHXI13:HYDROCARBONS
317892
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
1 \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\)
2 \(\mathrm{CH}_{4}\)
3 \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\)
4 \(\mathrm{CH} \equiv \mathrm{CH}\)
Explanation:
\({\text{(1) C}}{{\text{H}}_4}{\text{ + B}}{{\text{r}}_{\text{2}}}{\text{ }} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - Br + 2HBr}}\) \({\text{(2) 2C}}{{\text{H}}_{\text{3}}}{\text{ - Br + }}\mathop {{\text{2Na}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - }}\mathop {{\text{C}}{{\text{H}}_{\text{3}}}{\text{ + 2NaBr}}}\limits_{{\text{(}}\,{\text{Less}}\,\,{\text{than}}\,\,{\text{four}}\,\,{\text{carbon)}}} }\limits_{} \) Option I will give hydrocarbon having four carbon atoms .Option 3 and 4 will undergoes addition reaction with \({\text{B}}{{\text{r}}_{\text{2}}}\)
NEET - 2018
CHXI13:HYDROCARBONS
317893
Assertion : Saturated hydrocarbons are chemically less reactive. Reason : All isomeric paraffins have same parent name.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Less reactivity of saturated hydrocarbons is due to presence of single bonds between carbon atoms. Paraffins (alkanes) may have straight chain or branched chain isomers which have different parent names. So, option (3) is correct.
CHXI13:HYDROCARBONS
317894
Select the incorrect statement.
1 Petroleum and natural gas are the main sources of alkanes.
2 Chloroethane on reduction with zinc and dil. HCl produces ethane.
3 In Wurtz reaction, the dry ethereal (free from moisture) solution is used as solvent.
4 Methane can be prepared by Kolbe's electrolysis in good yield.
Explanation:
Methane cannot be prepared by Kolbe's electrolysis because this method is suitable for preparation of symmetrical alkanes i.e., alkanes containing even number of carbon atoms. So, incorrect statement is (4).
317891
A sample of \({\text{4}}{\text{.50}}\,\,{\text{mg}}\) of unknown alcohol is added to \(\mathrm{CH}_{3} \mathrm{MgBr}\) when \(1.68 \mathrm{~L}\) of \(\mathrm{CH}_{4}\) at STP is obtained. The unknown alcohol is
1 Methanol
2 Ethanol
3 1-Propanol
4 1-Butanol
Explanation:
All the four options given are monohydric alcohols. When a monohydric alcohol is treated with \(\mathrm{CH}_{3} \mathrm{MgBr}\), the number of moles of \(\mathrm{CH}_{4}\) gas produced is a equal to the number of moles of alcohol If \(\mathrm{M}\) is the molecular weight of alcohol, then \(\dfrac{4.50}{\mathrm{M}}=\dfrac{1.68}{22.4}\) On solving, \({\text{M = 60}}\). Therefore, the unknown alcohol is Propan-1-ol.
CHXI13:HYDROCARBONS
317892
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
1 \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\)
2 \(\mathrm{CH}_{4}\)
3 \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\)
4 \(\mathrm{CH} \equiv \mathrm{CH}\)
Explanation:
\({\text{(1) C}}{{\text{H}}_4}{\text{ + B}}{{\text{r}}_{\text{2}}}{\text{ }} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - Br + 2HBr}}\) \({\text{(2) 2C}}{{\text{H}}_{\text{3}}}{\text{ - Br + }}\mathop {{\text{2Na}} \to {\text{C}}{{\text{H}}_{\text{3}}}{\text{ - }}\mathop {{\text{C}}{{\text{H}}_{\text{3}}}{\text{ + 2NaBr}}}\limits_{{\text{(}}\,{\text{Less}}\,\,{\text{than}}\,\,{\text{four}}\,\,{\text{carbon)}}} }\limits_{} \) Option I will give hydrocarbon having four carbon atoms .Option 3 and 4 will undergoes addition reaction with \({\text{B}}{{\text{r}}_{\text{2}}}\)
NEET - 2018
CHXI13:HYDROCARBONS
317893
Assertion : Saturated hydrocarbons are chemically less reactive. Reason : All isomeric paraffins have same parent name.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Less reactivity of saturated hydrocarbons is due to presence of single bonds between carbon atoms. Paraffins (alkanes) may have straight chain or branched chain isomers which have different parent names. So, option (3) is correct.
CHXI13:HYDROCARBONS
317894
Select the incorrect statement.
1 Petroleum and natural gas are the main sources of alkanes.
2 Chloroethane on reduction with zinc and dil. HCl produces ethane.
3 In Wurtz reaction, the dry ethereal (free from moisture) solution is used as solvent.
4 Methane can be prepared by Kolbe's electrolysis in good yield.
Explanation:
Methane cannot be prepared by Kolbe's electrolysis because this method is suitable for preparation of symmetrical alkanes i.e., alkanes containing even number of carbon atoms. So, incorrect statement is (4).
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