Question

1g of mg is heated strongly in a vessel contain 0.5g of oxygen to form mgo which of following statement is true a)1.5g mgo formed (b) 1.25 g mgo ( c) oxygen is completely consumed (d) 0.25g mg left unreacted​

Answer 1

Answer:

a because mgo is only one product in reaction

Answer 2

True statements are-

• 1.25 g MgO is formed.
• Oxygen is completely consumed.
• 0.25 g Mg is left unreacted.

Given

Mass of Mg = 1g

Mass of Oxygen taken = 0.5 g

Balanced reaction is -

2Mg + O₂ → 2MgO

Moles of Mg = Given weight/ molecular weight = 1/24

Moles of O₂ = 0.5 / 32 = 1/ 64

Moles of oxygen is less than moles of Magnesium, so limiting reagent is Oxygen. Hence oxygen will be completely consumed in the reaction.

Now,

32 g oxygen forms 80 g of MgO

1 g oxygen will forms 80/32 g MgO

0.5 g oxygen will forms 80 × 0.5 / 32 = 1.25 g MgO

Similarly,

32 g oxygen use 48 g of Mg for the reaction

0.5 g oxygen will use = 48/32 × 0.5 = 0.75 g Mg

Hence Mg left = 1g - 0.75 g = 0.25 g Mg left

Regards