MCQ
Which substance has the highest melting point?
- A$CO$
- B$CO_2$
- C$SiO_2$
- D$P_2O_5$
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| $A$ | $B$ | $C$ | |
| $IE_1$ | $400$ | $550$ | $1150$ |
| $IE_2$ | $2650$ | $1070$ | $2090$ |
Identify the element which represent a nonmetal.
$(i)\,\mathop {\begin{array}{*{20}{c}}
{\,\,\,\,\,C{H_3}} \\
| \\
{C{H_3} - C - C{H_3}} \\
| \\
{\,\,\,\,\,C{H_3}}
\end{array}}\limits_{(Neo - pen\tan e)\,(i)} $
$(ii\mathop {)\,\begin{array}{*{20}{c}}
{C{H_3} - CH - C{H_2} - C{H_3}} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,\,\,\,C{H_{3\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}}}
\end{array}}\limits_{(Iso - pen\tan e)\,\,(ii)} $
$(iii)\,\mathop {C{H_3} - C{H_2} - C{H_2} - C{H_2} - C{H_3}}\limits_{(n - pen\tan e)} $
Assertion $(A) :$ At $10^{\circ} C$, the density of a $5\, M$ solution of $KCl$ [atomic masses of $K$ and $Cl$ are $39$ and $35.5\, g \,mol ^{-1}$ ]. The solution is cooled to $-21^{\circ} C$. The molality of the solution will remain unchanged.
Reason $(R):$ The molality of a solution does not change with temperature as mass remains unaffected with temperature.
In the light of the above statements, choose the correct answer from the options given below