Question

Cecil writes the equation for the reaction of hydrogen and oxygen below. H2 + O2 → H2O Why does his teacher ask him to balance the equation by including the correct coefficients? to show that most molecules exist in pairs to show that most compounds exist in pairs to show that atoms are conserved in chemical reactions to show that atoms are created in chemical reactions

Answer 1

In every chemical reaction mass remains constant.(law of conservation of mass)

If you direct write H2 +O2 = H2O, Then it will be considered as skeleton equation.

Here, H2 mass is 1×2=2

O2 mass is 16×2=32

SUM OF reactants = 2 +32= 34

But mass of product is 1×2+16=18

LHS NOT EQUAL TO RHS

therefore IT DOES NOT FOLLOW LAW OF CONSERVATION OF MASS ( I.E. NOT POSSIBLE)

WE MUST BALANCE IT

NOW 2H2 + O2 -> 2H2O

2 ×2 ATOMS OF HYDROGEN PLUS 2 ATOMS OF OXYGEN GIVES 2×2 ATOMS OF HYDROGEN PLUS 2×1 ATOMS OF OXYGEN

HOPE FRIEND THIS WILL WORK FOR YOU.

GOOD LUCK.

Answer 2

Answer: C. To show that atoms are conserved in chemical reactions.

I just took the test, I went back and look at the answers I got wrong, this was one of them, and the correct answer I should have picked was C.