What is the mass of 5.43x1045 molecules of beo

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