Question

Five moles of helium are mixed with two moles of hydrogen to form a mixture. Take molar mass of helium $M_1=4g$ and that of hydrogen $M_2=2g$
The equivalent degree molar mass of the mixture is............

• A. $3.57$
• B. $1.14$
• C. $4.4$
• D. none

Answer 1

Answer: (A)

$3.57$

Equivalent molar mass $=\frac{\sum n_i{m}_i}{\sum n_i}=\frac{\sum 5\times 4+2\times 2}{\sum 5+2}=\frac{24}{7}=3.42$.