In order to start to think about making calculations, it is important to familiarize yourself with reference tools that are available. The following link will connect you with the Chemistry reference tool for the STAAR chemistry exam.

Chemistry Reference

Answer the following questions in your notes. After attempting to answer the questions, self-check your answers below.

  1. Which page has the equation for the ideal gas law? Interactive popup. Assistance may be required.

    Check Your Answer

    Page 1Close Pop Up
  2. What does STP mean? Interactive popup. Assistance may be required.

    Check Your Answer

    Standard Temperature and PressureClose Pop Up
  3. If we are given the pressure in KiloPascals (kPa) which value would we use for the ideal gas constant? Interactive popup. Assistance may be required.

    Check Your Answer

    8.31 L * kPa mol * k Close Pop Up
  4. You have been asked to find the temperature change using the ideal gas law, however you have been given the temperature in °C and you need K, what information can help you convert the °C to K? Interactive popup. Assistance may be required.

    Check Your Answer

    07°C = 273KClose Pop Up
  5. How is using this reference tool helpful?

Manipulating the Ideal Gas Law Equation

The ideal gas law is represented using the following equation:

text: PV = nRT

However, when you are asked to calculate information using an equation, more often than not, you will have to manipulate (or change) the equation to find what you need. Remember when solving for a particular item, the goal is to get the item alone on one side of the "equals" sign.

Using the cards provided, take a few moments to see if you can come up with the correct equation for the item you are solving for. Drag the cards given into the final formula section in the order that you think they would represent the new modified formula. When you get the cards in the correct order, the correct equation will appear in the answer box.

Scenario 1: You have been given the following information: pressure, volume, moles (n), and the constant (R). What equation would you use to find the temperature?

Interactive exercise. Assistance may be required.Click here to begin the activity.

Scenario 2: You have been given the following information: volume, moles (n), temperature, and the constant (R). What equation would you use to find the pressure?

Interactive exercise. Assistance may be required. Click here to begin the activity.

Scenario 3: You have been given the following information: pressure, moles (n), temperature, and the constant (R). What equation would you use to find the volume?

Interactive exercise. Assistance may be required. Click here to begin the activity.

Scenario 4: You have been given the following information: volume, temperature, pressure, and the constant (R). What equation would you use to find the moles (n)?

Interactive exercise. Assistance may be required. Click here to begin the activity.

When you have completed the above activity, click below to see the reference table. Interactive popup. Assistance may be required.

Ideal Gas Law Equation "Solving For" Reference Table

Original Ideal Gas Law Equation (PV) = (nRT)
Solving for Temperature T = (PV)/(nR)
Solving for Pressure P = (nRT)/V
Solving for Volume V = (nRT)/P
Solving for Moles (n) n = (PV)/(RT)
Close Pop Up