Question

An organic compound has C and H percentage in the ratio $6:1$ by mass and C and O percentage in the ratio $3:4$ by mass. The compound is:

• A. $HCHO$
• B. $C{H}_{3}OH$
• C. $C{H}_{3}C{H}_{2}OH$
• D. $(COOH{)}_2$

Answer 1

The correct option is A $HCHO$

An organic compound has C and H percentage in the ratio $6:1$ by mass and C and O percentage in the ratio $3:4$ by mass. Thus, the compound will contain 6 g of C for each g of H and 8 g of O. The atomic masses of C, H and O are 12 g/mol, 1 g/mol, 16 g/mol respectively.
The number of moles of C $=\frac{6/g}{12g/mol}=0.5$ mol.
The number of moles of H $=\frac{1/g}{1g/mol}=1$ mol.
The number of moles of O $=\frac{8/g}{16g/mol}=0.5$ mol.
The mole ratio $C:H:O=0.5:1:0.5=1:2:1$
Hence, the compound is $C{H}_{2}O$ or $HCHO$