How does the oxidation state of na change in the following reaction?
li(s) + naoh(aq) → lioh(aq) + na(s)

The oxidation number increases from 0 to +1.

Explanation:

The important rules for oxidation numbers are:

Thus, in your reaction, the oxidation numbers are:

The oxidation number of Li increases from 0 to +1.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.