I am supposed to show all my work. but I forgot how to do everything other than balance it. 2.1g H2 reacts with 3.5g CO2 in a synthesis reaction in a 3.5 L solution

Write the balanced equation
Determine the limiting reagent (LR)
What is the molarity of the solution (based on the LR)?
[H3O+] = ?
[OH-] = ?

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.