Download App

Mole concept and Stoichiometry — Chemistry STD 10 — Question

ICSE BoardEnglish MediumSTD 10ChemistryMole concept and Stoichiometry1 Mark
MCQ
A compound with empirical formula AB2 has the vapour density equal to its empirical formula weight. Its molecular formula is:
  • A
    A2B2
  • B
    A2B4
  • C
    A2B3
  • D
    A2B8
✓

Answer

B. $A _2 B_4$
Explanation :
Given,
Empirical formula $= AB _2$
Vapour density $=\frac{\text { Molecular weight }}{2}$
Molecular weight $=2 \times VD$
According to the question,
Vapour density $=$ Empirical formula weight
Molecular formula $=($ Empirical formula $) n$
$\begin{array}{l}
n=\frac{\text { Molecular weight }}{\text { Empirical formula weight }} \\
=\frac{2 \times VD}{VD} \\
n=2
\end{array}$
So, molecular formula $=\left( AB _2\right)_2$
$=A_2 B_4$
Hence, the molecular formula is $A _2 B_4$.

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 "MCQ" from Mole concept and Stoichiometry→Mole concept and Stoichiometry — all question types→Chemistry STD 10 question papers→ICSE Board STD 10 question papers→ICSE Board question paper generator→

Similar questions

The particles present in strong electrolytes are:
→
The simplest formula of a compound containing $50 \%$ of element $X$ (atomic mass 10 ) and $50 \%$ of element $Y$ (atomic mass 20) is:
→
The acid produced by the reaction of phosphorus pentoxide with HCl gas is:
$POCl _3$ is not acidic, and hence the acidic product is $HPO _3$.
→
Covalent bond is formed between :
→
A black coloured powder which dissolves in dilute sulphuric acid to form a blue coloured solution, without evolution of any gas is :
→
Electrovalent compounds are :
→
An oxide which dissolves in water forming an acid.
→
Three compounds are shown below. Choose the correct option.
A = CH3-CH2-CHO B = CH3-CH2-CH2-OH C = CH3-CO-CH3
→
Which one is colourless anion?
→
Element $M$ forms a chloride with the formula $MCl _2$ which is a solid with high melting point. $M$ would most likely be in the group in which $...............$ is placed.
→