Which law can be used to calculate the number of moles of a contained gas when pressure, volume, and temperature are known?

• A. The Ideal Gas Law
• B. Charles's Law
• C. Avogadro's Law
• D. Boyle's Law

Answer: (A)

Verified step by step guidance

1. Identify the variables given in the problem: pressure (P), volume (V), and temperature (T).
2. Recall that the Ideal Gas Law relates pressure, volume, temperature, and number of moles (n) of a gas in one equation: \(P \times V = n \times R \times T\).
3. Understand that \(R\) is the ideal gas constant, which has a fixed value depending on the units used for pressure, volume, and temperature.
4. Rearrange the Ideal Gas Law to solve for the number of moles \(n\): \(n = \frac{P \times V}{R \times T}\).
5. Use this formula to calculate the number of moles when pressure, volume, and temperature are known, confirming that the Ideal Gas Law is the correct law to use.