# Under constant temperature, a 5.00*L volume of gas at 1*atm pressure is compressed to 3.00*L. What is the new pressure?

${P}_{1} {V}_{1} = {P}_{2} {V}_{2}$ (Boyle's law, pressure is inversely proportional to volume at constant temperature.)
${P}_{2} = \frac{{P}_{1} {V}_{1}}{V} _ 2$ $=$ $\frac{1 \cdot a t m \times 5.00 L}{3.00 L}$ $=$ $\left(\frac{5}{3} a t m\right)$.