Question

Most metals are very reactive, as are the elements in the halogen group. Aluminum, for instance, For example, reacts with elemental chlorine to form aluminum chloride. If you have a 13.5 g sample of Al, which choice below is true?
A. you will need 23.6 g Cl2 for complete reaction and will produce 66.7 g of AlCl3.
B. you will need 53.2 g Cl2 for complete reaction and will produce 66.7 g of AlCl3.
C. you will need 11.8 g Cl2 for complete reaction and will produce 49.0 g of AlCl3.
D. you will need 26.6 g Cl2 for complete reaction and will produce 49.0 g of AlCl3. Reset Selection

Answer 1

Answer:  B. you will need 53.2 g Cl2 for complete reaction and will produce 66.7 g of AlCl3.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles of aluminium}=\frac{\text{Given mass}}{\text {Molar mass}}=\frac{13.5g}{27g/mol}=0.5moles$

The balanced reaction is:

$2Al+3Cl_2(g)\rightarrow 2AlCl_3$

2 moles of aluminium react with= 3 moles of chlorine

Thus 0.5 moles of aluminium react with=$\frac{3}{2}\times 0.5=0.75$  moles of chlorine

Mass of chlorine=$moles\times {\text{Molar Mass}}=0.75\times 71=53.2g$

2 moles of aluminium produce = 2 moles of aluminium chloride

Thus 0.5 moles of aluminium react with=$\frac{2}{2}\times 0.5=0.5$  moles of aluminium chloride

Mass of aluminium chloride=$moles\times {\text{Molar Mass}}=0.5\times 133.34=66.7g$

Thus 53.2 g of chlorine is used and 66.7 g of  aluminium chloride is produced.