Question

3 g of Mg is burnt in a closed container which contains 8 g of O2 i.) which reactant is left in excess. (ii.)Find the mass of excess reactant. Iii)How much of Magnesium oxide is produce?​

Answer 1

Answer:

1 g of Mg is burnt in a closed vessel containing 0.5 g of O  

2

​  

. Which reactant is limiting how much of the reagent and excess reactant will be left?

Explanation:

Balanced reaction is:

2Mg+O  

2

​  

→2MgO

According to the reaction 2 mol (or 2×24.3=48.6g) Mg reacts with 32 g oxygen. 1 g of Mg requires =  

48.6

32

​  

=0.66g oxygen but given oxygen is 0.5 g ∴ oxygen is the limiting reagent

0.5 g oxygen can burn ==  

32

48.6

​  

×0.5=0.75g Mg

Excess of Mg left =1−0.75=0.25g

YOUR QUESTION IS RELATED TO THIS QUESTION.PLEASE COMPARE AND GET YOUR ANSWER.

Answer 2

Answer:

1. O2 is left in excess.
2. 8-2=6g of Oxygen is left.
3. 5g of magnesium oxide is produced.

Explanation:

2Mg+O2--->2MgO

48g 32g---->80g

3g 8g

Hence Magnesium is the limiting reactant as 3g Mg requires 2g oxygen to burn but amount of oxygen given =8g for which 3g Mg would be consumed first and Oxygen is the excess reactant.

Amount of Oxygen left=8-2=6g=mass of excess reactant.

Hence magnesium would decide the amount of reactant to be formed.

Since 48g Mg gives 80 gms of Magnesium oxide then 3 g Magnesium would give = 80×3/48gms=5gms of Magnesium oxide would be formed.