Answer:
The number of mole is 2.422 moles
Step-by-step explanation:
To calculate the number of mole, we have to use the formula n = m /Mm
n - moles
m - mass
Mm - molar mass
Let's calculate the molar mass of the compound SiO2
Si - 28.0855
O - 15.999
Note: there are two atoms of oxygen in the compound
Mm of SiO2= 28.0855+ 2* 15.999
= 60.0835g/mol
Now, we calculate the number of moles
n = 145.54g/ 60.0835g/mol
= 2.422mol