MCQ
Whether a reaction is endothermic or exothermic can be indicated by :
- ✓Enthalpy change.
- BEntropy change.
- CActivation energy.
- DSpecific heat capacity.
✓
Answer
Correct option: A.
Enthalpy change.
Whether a reaction is endothermic or exothermic can be indicated by enthalpy change.
Enthalpy change is the difference in the enthalpy of products and the enthalpy of reactants.
A positive value of enthalpy change indicates endothermic reaction as the enthalpy of products is more than the enthalpy of reactants.
A negative value of enthalpy change indicates exothermic reaction as the enthalpy of products is less than the enthalpy of reactants.
Enthalpy change is the difference in the enthalpy of products and the enthalpy of reactants.
A positive value of enthalpy change indicates endothermic reaction as the enthalpy of products is more than the enthalpy of reactants.
A negative value of enthalpy change indicates exothermic reaction as the enthalpy of products is less than the enthalpy of reactants.
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
The given pair are
$\begin{array}{*{20}{c}}
{C{H_3} - CH - CH = C{H_2} + HBr \to X\,\left( {major\,product} \right)} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}$
→{C{H_3} - CH - CH = C{H_2} + HBr \to X\,\left( {major\,product} \right)} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}$
$X$ is
Which of the following isoelectronic series would lose an electron most easily ?
The above diagram represents :
The second electron gain enthalpies (in $kJ\, mol^{-1}$ ) of oxygen and sulphur respectively are
→If $50\,ml$ of $0.2\,M\,KOH$ is added to $40\,ml$ of $0.5\,M\,HCOOH,$ the $pH$ of the resulting solution is $({K_a} = 1.8 \times {10^{ - 4}})$
→Consider the figure provided.
→$1 \mathrm{~mol}$ of an ideal gas is kept in a cylinder, fitted with a piston, at the position $\mathrm{A}$, at $18^{\circ} \mathrm{C}$. If the piston is moved to position $B$, keeping the temperature unchanged, then ' $x$ ' $L$ atm work is done in this reversible process.
$\mathrm{x}=$ . . . . . . $\mathrm{L} \mathrm{atm.} \mathrm{(nearest} \mathrm{integer)}$
[Given : Absolute temperature $={ }^{\circ} \mathrm{C}+273.15$, $\left.\mathrm{R}=0.08206 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}\right]$
Which of the following can show geometrical isomerism ?
The liquefied metal which expands on solidification is
The correct order of bond enthalpy $\left( kJ\,mol ^{-1}\right)$ is :
→