The table shows the results of adding three metals, P, Q and R

The answer is 3,5g co

Must be negative.substance increases

Combustion is the act or process of burning. therefore, i believe the answer is  a: burning wood. 

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.