Which equation represents the law of conservation of energy in a closed system

Which statement can best be concluded from the ideal gas law?

What is the pressure of 0.500 moles of carbon dioxide gas in a 2.5 l tank and at a temperature of 301 k? (r=0.0821 l·atm/mol·k) 3.08 atm 1.2 atm 0.23 atm 4.01 atm 4.94 atm

The primary products of complete combustion of fossil fuels are a. carbon dioxide and water b. methane and water c. carbon monoxide and water d. carbon dioxide and carbon monoxide