Question

how many atoms are present in 9.0 g of aluminium [atomic mass of aluminium = 27u]

Answer 1

Answer:

$2.00 \times 10^{23}$ atoms  are present in  9 gram of aluminium.

Explanation:

• ‘Molecular or molar mass’ of the element is the “mass of one mole” of an element $=6.022 \times 10^{23}$ atoms.

• The molecular mass of aluminium  = 27g

Number of moles =  Mass of the given substance / mass of one mole

N $=\frac{9}{27}$ = 0.333 mol.

• To convert the moles into atoms, the number of moles calculated should be multiplied by the molecular mass of ‘one mole of the element’ or the Avagadro’s number, $6.022 \times 10^{23}$ atoms.

• So the number of atoms in 9.0 g of aluminium $=0.333 \times 6.022 \times 10^{23}$atoms.

$=2.00 \times 10^{23}$ atoms.

Answer 2

Answer:

Here is your answer mate....