Answer:
2.255 x 10²³ g
Explanation:
Data Given:
no. of molecules of BeO = 5.43 x 10⁴⁵ molecules
mass of BeO = ?
Solution:
first we will find no. of moles
Formula used
no. of moles = no. of molecules / Avogadro's number
Where
Avogadro's number = 6.022 x 10²³
Put values in above equation
no. of moles = 5.43 x 10⁴⁵ molecules / 6.022 x 10²³ (molecules/mol)
no. of moles = 9.02 x 10²¹ mol
So,
There are 9.02 x 10²¹ moles of BeO of 5.43x10⁴⁵
Now we will find the mass
For this formula will be used
No. of moles = Mass in grams/ molar mass
Rearrange the above equation
mass in grams = no. of moles x molar mass . . . . . (1)
molar mass of BeO = 9 + 16 = 25 g/mol
Put values in equation 1
mass in grams = 9.02 x 10²¹ moles x 25 g/mol
mass in grams = 2.255 x 10²³ g
So,
Mass of 5.43 x 10⁴⁵ molecules of BeO = 2.255 x 10²³ g
