Download App

1. Some basic concept of chemistry — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistry1. Some basic concept of chemistry1 Mark
MCQ
Compound $A$ contains $8.7\, \%$ Hydrogen, $74\, \%$ Carbon and $17.3\,\%$ Nitrogen. The molecular formula of the compound is ....

Given : Atomic masses of $C , H$ and $N$ are $12,1$ and $14\, amu$ respectively.

The molar mass of the compound $A$ is $162\, g\, mol ^{-1}$.

  • A
    $C _{4} H _{6} N _{2}$
  • B
    $C _{2} H _{3} N$
  • C
    $C _{5} H _{7} N$
  • ✓
    $C _{10} H _{14} N _{2}$
✓

Answer

Correct option: D.
$C _{10} H _{14} N _{2}$
d
$C$ $74 \,\%$ $\frac{74}{12}=6.16$ $\frac{6.16}{1.23}=5$
$N$ $17.3\, \%$ $\frac{17.3}{14}=1.23$ $\frac{1.23}{1.23}=1$
$H$ $8.7 \,\%$ $\frac{8.7}{1}=8.7$ $\frac{8.7}{1.23}=7$

Emperical formula $= C _{5} NH _{7}$

Emperical weight $=81$

Multiplying factor $=\frac{162}{81}=2$

Molecular formula $= C _{10} N _{2} H _{14}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 1. Some basic concept of chemistry→1. Some basic concept of chemistry — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Which of the following compound will not undergo tautomerism?
→
The total amount of energy in the universe is fixed, but
→
The solubility product of $Ag_2CO_3$ and $FeCO_3$ in water at $25\,^oC$ are $4 \times 10^{-12}$ and $2.5 \times 10^{-11}$ respectively. If $S_1$ and $S_2$ are their solubilities in water respectively when dissolved separately, then $S_1/S_2$ is
→
Which one is a wrong statement ?
→
Decreasing order of acidic strength of different $(-OH)$ groups is
→
Assertion : Nitrating mixture used for carrying out nitration of benzene consists of conc. $HNO_3+$ conc. $H_2SO_4$.

Reason : In presence of $H_2SO_4$, $HNO_3$ acts as a base and produces $NO_2^+$ ions.

→
The maximum number of unpaired electron can be present in $d$-orbitals are
→
Which of the following has the highest melting point
→
The dissociation constants of monobasic acids $A, B, C$ and $D$ are $6 \times 10^{-4}, 5 \times 10^{-5}, 3.6 \times 10^{-6}$ and $7 \times 10^{-10}$ respectively. The $pH$ values of their $0.1\, molar$ aqueous solutions are in the order
→
Which one is polar molecule among the following
→