Page 705 #12/#13: use the changes in oxidation numbers to identify which atom is oxidized, reduced, the oxidizing agent, and the reducing agent. 5

a.
2h2(g) + o2(g) → 2h2o(l)

b.
2kno3(s) → 2kno2(s) + o2(g)

Concepts to understand before solving:

-Oxygen is ALWAYS reduced

-OIL- Oxidation Is Loss of electrons

-RIG- Reduction Is Gain of electrons

-the element that is oxidized is the reducing agent

-the element that is reduced is the oxidizing agent

A. 2H2 + O2 —> 2H2O

O is reduced, making it the oxidizing agent

H is oxidized, making it the reducing agent

B. 2KNO3 —> 2KNO2 + O2

O is reduced, making it the oxidizing agent

KNO is oxidized, making it the reducing agent

answer; /// the amount of material dissolved in a measure of liquid(concentration) the above statement is (true); /// good luck

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.