Question

When an object is burning , two atoms of oxygen ( in the air) combine with one atom of carbon (from the substance burning). This form carbon dioxide gas. Explain how the law of conservation if matter applied to this reaction.

Answer 1

Answer:

If matter is applied to the combustion reaction , then total mass is constant . This means mass of reactants and product are same.

Explanation:

Law of Conservation of mass : It states that mass can neither be created nor destroyed during the chemical reaction. Thus , total mass of the reactant is equal to the total mass of the reactant.(or total number of atoms of  in reactant and products must be equal)

Let's start from the simple equation first :The combustion reaction

$C(s)+O_{2}(g)\rightarrow CO_{2}(g)$

Count the atoms in Reactant (C , O2)

In C = 1 atom of carbon

O2 = 2 atoms of Oxygen

Atoms in product (CO2)

In CO2 ,

atoms of C = 1

atoms of O = 2

Hence total number of C and O atoms in reactant and product are same . So this reaction follow the law of conservation of mass.

Note that , Only those reaction will take place that follow law of conservation of mass.

To explain :

Explain how the law of conservation if matter applied to this reaction.?

For example:

Consider the combustion of Methane (CH4)

"CH4 is the matter"

The balanced equation is :

$CH_{4}+2O_{2}(g)\rightarrow CO_{2}(g)+2H_{2}O$

Now check the number of atoms of each element in reactant and product side.

Reactants : CH4 and 2 O2

C atoms = 1  

H atom = 4

O atom = 2(2) = 4    (2 x 2 from oxygen)

Product : CO2 and 2H2O

C atom = 1 (from Co2)

O atom = 2 from CO2 + 2 from H2O

O atom= 2+ 2 = 4 atoms

H atom = 2 x(2 atoms from H2O)

H atom = 4

Since total number of atoms in reactant = total number of atoms in product.

So this equation follow the Law of Conservation of mass

And the atoms are

C= 1

O=4

H =4