Question

Calculate the mass of arsenic trihydride produced from 117.4 g of hydrogen gas with excess arsenic trioxide:

Answer 1

Answer: The mass of
`AsH_3` produced is, 1528.8 grams.

Explanation : Given,

Mass of
`H_2` = 117.4 g

Molar mass of
`H_2` = 2 g/mol

First we have to calculate the moles of
`H_2`.

`\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}`

`\text{Moles of }H_2=(117.4g)/(2g/mol)=58.7mol`

Now we have to calculate the moles of
`AsH_3`

The balanced chemical equation is:

`6H_2+As_2O_3\rightarrow 2AsH_3+3H_2O`

From the reaction, we conclude that

As, 6 moles of
`H_2` react to give 2 moles of
`AsH_3`

So, 58.7 moles of
`H_2` react to give
`(2)/(6)* 58.7=19.6` mole of
`AsH_3`

Now we have to calculate the mass of
`AsH_3`

`\text{ Mass of }AsH_3=\text{ Moles of }AsH_3* \text{ Molar mass of }AsH_3`

Molar mass of
`AsH_3` = 78 g/mole

`\text{ Mass of }AsH_3=(19.6moles)* (78g/mole)=1528.8g`

Therefore, the mass of
`AsH_3` produced is, 1528.8 grams.