NEET Test Series from KOTA - 10 Papers In MS WORD
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Hydrocarbons
230403
The most stable alkene is:
1 $\mathrm{R}_2 \mathrm{C}-\mathrm{CR}_2$
2 $\mathrm{RCH}-\mathrm{CHR}$
3 $\mathrm{CH}_2-\mathrm{CH}_2$
4 $\mathrm{RCH}-\mathrm{CR}_2$
Explanation:
: The more substituted alkene is more stable than less substituted alkene. Alkene is more reactive due to the presence of double bond. So, more the number of electron releasing group of alkyl on the double bond lesser is the stability.
BCECE-2004]
Hydrocarbons
230405
Which one of the following will most readily be dehydrated in acidic conditions?
1
2
3
4
Explanation:
: The stability increase then greater the conjugation. B-hydroxyaldehydes or $\beta$-hydroxyletones readily undergoes dehydrodion of from more stable $\alpha, \beta$ - unsaturated aldehydes or ketones.
BCECE-2008
Hydrocarbons
230406
Ethyl chloride on treatment with alcoholic alleali gives
1 $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}$
2 $\mathrm{C}_2 \mathrm{H}_5$
3 $\mathrm{CH}_3 \mathrm{CHO}$
4 $\mathrm{CH}_2-\mathrm{CH}_2$
Explanation:
: Ethyl chloride can undergo both nucleophilic substitution as well as elimination reaction with strong alkali like $\mathrm{KOH}$. When it undergoes nucleophilic substitution, ethyl alcohol is formed as major product $\mathrm{C}_2 \mathrm{H}_5 \mathrm{Cl}+\mathrm{KOH}(\mathrm{aq}) \longrightarrow \mathrm{C}_2 \mathrm{H}_3 \mathrm{OH}+\mathrm{KCl}$
BCECE-2009
Hydrocarbons
230407
In which of the following can peroxide effect operate?
: Peroxide effect is also known as kharasch effect. When unsymmetrical alkene react with alkyl halide (only presence of $\mathrm{HBr}$ ) in the presence of peroxide and reaction proceed via a free radical mechanism. $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}=\mathrm{CH}_2+\mathrm{HBr} \stackrel{\mathrm{ni}_2 \mathrm{O}}{\longrightarrow} \mathrm{CH}_5-\mathrm{CH}_2-\mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}$
: The more substituted alkene is more stable than less substituted alkene. Alkene is more reactive due to the presence of double bond. So, more the number of electron releasing group of alkyl on the double bond lesser is the stability.
BCECE-2004]
Hydrocarbons
230405
Which one of the following will most readily be dehydrated in acidic conditions?
1
2
3
4
Explanation:
: The stability increase then greater the conjugation. B-hydroxyaldehydes or $\beta$-hydroxyletones readily undergoes dehydrodion of from more stable $\alpha, \beta$ - unsaturated aldehydes or ketones.
BCECE-2008
Hydrocarbons
230406
Ethyl chloride on treatment with alcoholic alleali gives
1 $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}$
2 $\mathrm{C}_2 \mathrm{H}_5$
3 $\mathrm{CH}_3 \mathrm{CHO}$
4 $\mathrm{CH}_2-\mathrm{CH}_2$
Explanation:
: Ethyl chloride can undergo both nucleophilic substitution as well as elimination reaction with strong alkali like $\mathrm{KOH}$. When it undergoes nucleophilic substitution, ethyl alcohol is formed as major product $\mathrm{C}_2 \mathrm{H}_5 \mathrm{Cl}+\mathrm{KOH}(\mathrm{aq}) \longrightarrow \mathrm{C}_2 \mathrm{H}_3 \mathrm{OH}+\mathrm{KCl}$
BCECE-2009
Hydrocarbons
230407
In which of the following can peroxide effect operate?
: Peroxide effect is also known as kharasch effect. When unsymmetrical alkene react with alkyl halide (only presence of $\mathrm{HBr}$ ) in the presence of peroxide and reaction proceed via a free radical mechanism. $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}=\mathrm{CH}_2+\mathrm{HBr} \stackrel{\mathrm{ni}_2 \mathrm{O}}{\longrightarrow} \mathrm{CH}_5-\mathrm{CH}_2-\mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}$
: The more substituted alkene is more stable than less substituted alkene. Alkene is more reactive due to the presence of double bond. So, more the number of electron releasing group of alkyl on the double bond lesser is the stability.
BCECE-2004]
Hydrocarbons
230405
Which one of the following will most readily be dehydrated in acidic conditions?
1
2
3
4
Explanation:
: The stability increase then greater the conjugation. B-hydroxyaldehydes or $\beta$-hydroxyletones readily undergoes dehydrodion of from more stable $\alpha, \beta$ - unsaturated aldehydes or ketones.
BCECE-2008
Hydrocarbons
230406
Ethyl chloride on treatment with alcoholic alleali gives
1 $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}$
2 $\mathrm{C}_2 \mathrm{H}_5$
3 $\mathrm{CH}_3 \mathrm{CHO}$
4 $\mathrm{CH}_2-\mathrm{CH}_2$
Explanation:
: Ethyl chloride can undergo both nucleophilic substitution as well as elimination reaction with strong alkali like $\mathrm{KOH}$. When it undergoes nucleophilic substitution, ethyl alcohol is formed as major product $\mathrm{C}_2 \mathrm{H}_5 \mathrm{Cl}+\mathrm{KOH}(\mathrm{aq}) \longrightarrow \mathrm{C}_2 \mathrm{H}_3 \mathrm{OH}+\mathrm{KCl}$
BCECE-2009
Hydrocarbons
230407
In which of the following can peroxide effect operate?
: Peroxide effect is also known as kharasch effect. When unsymmetrical alkene react with alkyl halide (only presence of $\mathrm{HBr}$ ) in the presence of peroxide and reaction proceed via a free radical mechanism. $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}=\mathrm{CH}_2+\mathrm{HBr} \stackrel{\mathrm{ni}_2 \mathrm{O}}{\longrightarrow} \mathrm{CH}_5-\mathrm{CH}_2-\mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}$
: The more substituted alkene is more stable than less substituted alkene. Alkene is more reactive due to the presence of double bond. So, more the number of electron releasing group of alkyl on the double bond lesser is the stability.
BCECE-2004]
Hydrocarbons
230405
Which one of the following will most readily be dehydrated in acidic conditions?
1
2
3
4
Explanation:
: The stability increase then greater the conjugation. B-hydroxyaldehydes or $\beta$-hydroxyletones readily undergoes dehydrodion of from more stable $\alpha, \beta$ - unsaturated aldehydes or ketones.
BCECE-2008
Hydrocarbons
230406
Ethyl chloride on treatment with alcoholic alleali gives
1 $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}$
2 $\mathrm{C}_2 \mathrm{H}_5$
3 $\mathrm{CH}_3 \mathrm{CHO}$
4 $\mathrm{CH}_2-\mathrm{CH}_2$
Explanation:
: Ethyl chloride can undergo both nucleophilic substitution as well as elimination reaction with strong alkali like $\mathrm{KOH}$. When it undergoes nucleophilic substitution, ethyl alcohol is formed as major product $\mathrm{C}_2 \mathrm{H}_5 \mathrm{Cl}+\mathrm{KOH}(\mathrm{aq}) \longrightarrow \mathrm{C}_2 \mathrm{H}_3 \mathrm{OH}+\mathrm{KCl}$
BCECE-2009
Hydrocarbons
230407
In which of the following can peroxide effect operate?
: Peroxide effect is also known as kharasch effect. When unsymmetrical alkene react with alkyl halide (only presence of $\mathrm{HBr}$ ) in the presence of peroxide and reaction proceed via a free radical mechanism. $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}=\mathrm{CH}_2+\mathrm{HBr} \stackrel{\mathrm{ni}_2 \mathrm{O}}{\longrightarrow} \mathrm{CH}_5-\mathrm{CH}_2-\mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}$
