Calculation of Molecular Mass — lesson. Science State Board, Class 10.

PDF chapter test TRY NOW

Calculate the gram molecular mass of the following compounds.

$H_2O$

ii.

$CO_2$

iii.

$(Ca)_3(PO_4)_2$

$H_2O$

Data:

Atomic mass of

$H=1$

Atomic mass of

$O=16$

Solution:

$\begin{array}{l} Gram molecular mass of H_{2} O \\ = (2 \times 1) + (1 \times 16) \\ = 2 + 16 \\ = 18 \end{array}$

Hence, the gram molecular mass of

$H_2O=18$

$g$ .

ii.

$CO_2$

Data:

Atomic mass of

$C=12$

Atomic mass of

$O=16$

Solution:

$\begin{array}{l} Gram molecular mass of {CO}_{2} \\ = (1 \times 12) + (2 \times 16) \\ = 12 + 32 \\ = 44 \end{array}$

Hence, the gram molecular mass of

$CO_2=44$

$g$ .

iii.

$(Ca)_3(PO_4)_2$

Data:

Atomic mass of

$Ca=40$

Atomic mass of

$P=30$

Atomic mass of

$O=16$

Solution:

$\begin{array}{l} Gram molecular mass of {Ca}_{3} {({PO}_{4})}_{2} \\ = (3 \times 40) + [30 + (4 \times 16)] \times 2 \\ = 120 + [30 + 64] \times 2 \\ = 120 + (94 \times 2) \\ = 308 \end{array}$

Hence, the gram molecular mass of

$(Ca)_3(PO_4)_2=308$

$g$ .

Previous theory

Exit to the topic

Next theory

Send feedback

Did you find an error?

Send it to us!

8. Calculation of Molecular Mass

Theory: