This type of chart will help you to determine which quantities are changing and

Question

This type of chart will help you to determine which quantities are changing and which quantities remain the same. For example, use the formula P1V1=P2V2 for the product of pressure and volume at two different points in time when pressure and volume are changing but the number of moles of gas and the temperature are constant. Here is how this formula is derived from the ideal gas law, PV=nRT: If n and T are constant, the entire quantity nRT is constant. Therefore, PV is constant. It follows that the quantity PV at any point in time will be the same value as at any other point in time. Therefore, P1V1=P2V2. Now imagine an experiment where your chart looks like this: Initial Final P 2 atm 2 atm V 1.7 L 2.5 L n 0.45 mol 0.45 mol T 273 K ? It is clear that V and T are the quantities that are changing, while P and n are constant. To put all constants P, n, and R together, we need to do a little bit of algebra: PV=nRT. V=nRTP. VT=nRP. VT is constant. Therefore the quantity V/T at any point in time will be the same value as at any other point in time, so V1T1=V2T2 This last equation is the best formula to use when only volume and temperature are changing. Now to solve for the missing value, simply substitute numbers into this formula: 1.7 L273 K=2.5 LT2 which gives T2=401.5 K Derive a gas law formula for a specific scenario One mole of an ideal gas is sealed in a 22.4-L container at a pressure of 1 atm and a temperature of 273 K. The temperature is then increased to 310. K , but the container does not expand. What will the new pressure be? Part A The most appropriate formula for solving this problem includes only which variables? Enter the required variables, separated by commas (e.g., P,V,T).

Explanation / Answer

PV = nRT

Here we kept V, n, and R constant.

SO, P / T = constant

For two different states,

P1 / T1 = P2 / T2

1 / 273 = P2 / 310

P2 = 1.14 atm

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.