Natural gas is a fuel that is used for heating and cooking in many homes and buildings. It is composed of almost pure methane, CH₄, and burns with a hot, blue flame. The chemical equation for the burning of methane is show below : CH4 + 2O2 → CO2 + 2H2O

Describe the burning of methane as a chemical reaction by explaining the following :

1. How can you tell from the chemical equation that this is a chemical reaction and not just a physical change ?

2.What observations would you see that indicate a chemical reaction?

3.is it an exothermic or endothermic reaction? What observation support your choice ?

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

56 moles of   lieter in chemistry

they vary. it used to be meat, grain, bread, candy, beverages, donuts, and fruits/vegetables. now they added exercise in.