Question
Explain cross aldol condensation.
✓
Answer
$(1)$ An aldol condensation between two different carbonyl compounds $($aldehydes and or ketones$)$ takes place even though one of the two carbonyl compounds molecules does not contain $a-$hydrogen atom e.g. $HCHO$ and $C_6H_5CHO.$
$(2)$ If both aldehydes or ketones contain two $a-$hydrogen atoms each, then a mixture of four products, is formed. For example, a mixture of ethanal and propanal on reaction with dilute alkali followed by heating gives a mixture of four products.
Self aldol condensation:
Cross aldol condensation:
$(2)$ If both aldehydes or ketones contain two $a-$hydrogen atoms each, then a mixture of four products, is formed. For example, a mixture of ethanal and propanal on reaction with dilute alkali followed by heating gives a mixture of four products.
Self aldol condensation:
Cross aldol condensation:
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Explain with diagram. Frenkel defect. What are the conditions for its formation? What is its effect on density and electrical neutrality of the crystal?
One mole of an ideal gas is compressed from $500\ cm^3$ against a constant external pressure of $1.2 \times 10^5$ Pa. The work involved in the process is $36.0\ J$ . Calculate the final volume.
→How will you distinguish between :
(1) Ethylamine, diethyl amine and triethyl amine by using (i) nitrous acid (ii) Hinsberg’s reagent.
(2) Diethyl amine and triethyl amine by using acetic anhydride.
(1) Ethylamine, diethyl amine and triethyl amine by using (i) nitrous acid (ii) Hinsberg’s reagent.
(2) Diethyl amine and triethyl amine by using acetic anhydride.
Predict whether the following
reactions would occur spontaneously
under standard state conditions.
a. $Ca_{(s)} + Cd^{2+}_{(aq)} \rightarrow Ca^{2+}_{(aq)} + Cd_{(s)}$
b. $2 Br-_{(s)} + Sn^{2+}(aq) \rightarrow Br_2_{(l)} + Sn_{(s)}$
c. $2Ag_{(s)} + Ni^{2+}_{(aq)} \rightarrow 2 Ag^+_{(aq)} + Ni_{(s)}$
→reactions would occur spontaneously
under standard state conditions.
a. $Ca_{(s)} + Cd^{2+}_{(aq)} \rightarrow Ca^{2+}_{(aq)} + Cd_{(s)}$
b. $2 Br-_{(s)} + Sn^{2+}(aq) \rightarrow Br_2_{(l)} + Sn_{(s)}$
c. $2Ag_{(s)} + Ni^{2+}_{(aq)} \rightarrow 2 Ag^+_{(aq)} + Ni_{(s)}$
What is meant by nucleosides?###Write the structure of nucleoside. Give examples.
What are ligands? What are their types? Give one example of each type.
Write the cell reaction and calculate cell potential and standard free energy change for a cell reaction in the following cell:
$\begin{aligned}
& A l _ { ( s ) } \left| A l _{( a q )}^{3+}(1 M ) \| C d _{( a q )}^{2+}(1 M )\right| C d \\
& E _{ Al ^{3+} / Al }^{0}=-1-66 V \text { and } E _{ cd ^2+/ cd }=-0.403 V
\end{aligned}$
→$\begin{aligned}
& A l _ { ( s ) } \left| A l _{( a q )}^{3+}(1 M ) \| C d _{( a q )}^{2+}(1 M )\right| C d \\
& E _{ Al ^{3+} / Al }^{0}=-1-66 V \text { and } E _{ cd ^2+/ cd }=-0.403 V
\end{aligned}$
Deduce the mathematical expression of first law of thermodynamics for the following processes :
$(1)$ Isothermal process
$(2)$ Isobaric process
$(3)$ Isochoric process
$(4)$ Adiabatic process.
→$(1)$ Isothermal process
$(2)$ Isobaric process
$(3)$ Isochoric process
$(4)$ Adiabatic process.
Answer the following
Explain the trends in atomic radii of d block elements.
Obtain a relation, $\log _{10} \frac{k_2}{k_1}=\frac{E_{ a }\left(T_2-T_1\right)}{2.303 R \times T_1 \times T_2}$,
###
Obtain a relation showing variation in rate constant with temperature.
→###
Obtain a relation showing variation in rate constant with temperature.