Question

36.0 g of Be contains how many moles?

Answer 1

Given Mass = 36.0 g

Molar Mass of Be = 9.0 g

$no. \: of \: moles = \frac{given \: mass}{molar \: mass} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{36}{9} \\ \: \: \: \: \: \: \: \: = 4$

Answer 2

Given :

Mass of Beryllium (Be) = 36 g

To Find :

Number of moles of beryllium

Solution :

Mole is defined as the number of particles (like atom,  molecules or ions) which is exactly equal to the number of ¹²C-atoms present in 0.012 Kg of carbon.

Number of moles = $\frac{Given Mass}{Molar Mass}$

Given mass of Be = 36 g

Molar mass of Be = 9 gm

∴ Number of moles present in 36 g of Be = $\frac{36}{9}$

                                                                     = 4

Therefore, the number of moles present in 36 g of Be is 4.