What is the final step in the scientific method

What’s the percent by mass of carbon in c10h14n2

In a reaction (at equilibrium) that makes more moles of gas than it consumes, what is the effect of increasing the pressure?

While in europe, if you drive 125 km per day, how much money would you spend on gas in one week if gas costs 1.10 euros per liter and your car’s gas mileage is 32.0 mi/gal? assume that 1 euro=1.26 dollars