We are given with the mass of Arsine (
![AsH_(3)](https://img.qammunity.org/2020/formulas/chemistry/middle-school/5d80amun0sfsganm509augx4exr7w5lcq6.png)
The mass of arsine is 15g
there is a relation between moles, mass and molar mass of any compound which is
![moles=(mass)/(molarmass)](https://img.qammunity.org/2020/formulas/chemistry/middle-school/a62h1fc7grch2xlqkjf7czeufmua398pg9.png)
The molar mass of Arsine = atomic mass of As + 3X atomic mass of H
the molar mass of Arsine = 74.92 + 3X 1 = 77.92 g/mol
Let us calculate the moles as
![moles=(15)/(77.92)=0.192mol](https://img.qammunity.org/2020/formulas/chemistry/middle-school/hvrs8ct9nvoixsbqyuay1ydw8tcvfo7ku2.png)