Question

calculate the mass of oxygen produced hen 2000kg of aluminium oxide is completely electrolysed

Answer 1

Answer:

Explanation:

(Mr of Al2O3 =) 102

2 000 000/102 =19 608 (mol Al2O3)

19 608 ×3/2 =29 412 (mol O2)

(29 412 × 32)/1000 = 941 (kg)

Answer 2

The mass of oxygen produced is 941.55 kg.

Explanation:

Given that:

• The mass of aluminum oxide Al₂O₃ = 2000 kg or 2000000 g
• Molar mass of Al₂O₃ = 101.96 g/mol

Therefore, the number of moles of Al₂O₃ present is,

• $No.ofmoles=\frac{Mass(g)}{Molar Mass(g/mol)}$  
• $No.ofmoles(Al_{2} O_{3} )=\frac{2000000}{101.96}$
• No of moles of Al₂O₃ = 19615.54 mol

From the reaction:

• $4Al+3O_{2} \rightarrow 2Al_{2}O_{3}$

Determining the moles of O₂ in Al₂O₃:

• Determining the moles of O₂ in Al₂O₃ = $19615.54 (mol)\times \frac{3}{2} (mol)$
• Determining the moles of O₂ in Al₂O₃ = 29423.30

Therefore,

• The mass of oxygen = 29423.30 × 32 g
• The mass of oxygen = 941545.7 g

Converting into kilograms:

• The mass of oxygen = $\frac{941545.7}{1000}$ kg

• The mass of oxygen = 941.55 kg

941.55 kg is the mass of oxygen produced when 2000 kg of aluminum oxide is completely electrolysed.