Simple Stoichiometry
| If you're having trouble with mole conversion problems (simple one-step and two-step stoichiometry problems), work your way through the following tutorial. Only the correct answer for each question will result in a response from this tutorial. |
Simple One-Step Mole Conversions
| In order to successfully navigate the various mole conversions, it is important to be able to identify your starting and ending points. Consider the following examples: | |||
| Example 1: How many moles are there in 2.55 g of water? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor...gfm, 22.4 L, or Avogadro's number. How will you convert your starting value into your ending value? | ||||
| You should now be ready to calculate the number of moles in 2.55 g of water. Click here to check your answer. |
| Example 2: What volume will 0.288 moles of oxygen gas have at STP? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor...gfm, 22.4 L, or Avogadro's number. How will you convert your starting value into your ending value? | ||||
| You should now be ready to calculate the volume of 0.288 moles of oxygen gas. Click here to check your answer. |
| Example 3: How many atoms are there in 1.55 moles of gold? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor...gfm, 22.4 L, or Avogadro's number. How will you convert your starting value into your ending value? | ||||
| You should now be ready to calculate the number of atoms in 1.55 moles of gold. Click here to check your answer. |
Simple Two-Step Mole Conversions
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Two-step mole conversions are just as easy to complete as the one-step conversions. The key things to remember are:
Consider the following examples: |
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| Example 4: How many molecules are there in 1.15 x 10-5 g of oxygen gas? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor for the first step...gfm, 22.4 L, or Avogadro's number. How will you make this first conversion? | ||||
| Now you need to identify the conversion factor for the second step of the conversion process. How will you make this conversion? |
| You should now be ready to calculate the number of molecules in 1.15 x 10-5 g of oxygen gas. Click here to check your answer. |
| Example 5: How much does 3.15 x 1019 formula units of aluminum oxide weigh? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor for the first step...gfm, 22.4 L, or Avogadro's number. How will you make this first conversion? | ||||
| Now you need to identify the conversion factor for the second step of the conversion process. How will you make this conversion? |
| You should now be ready to calculate the weight of 3.15 x 1019 formula units of aluminum oxide. Click here to check your answer. |
| Example 6: What is the volume of 10.5 g of nitrogen dioxide gas? | |||
| First, ask yourself, "What is my starting point? | |||
| Now that you've identified your starting point, you have to ask yourself, "What is my ending point?" | |||
| The next step involves identifying the appropriate conversion factor for the first step...gfm, 22.4 L, or Avogadro's number. How will you make this first conversion? | ||||
| Now you need to identify the conversion factor for the second step of the conversion process. How will you make this conversion? |
| You should now be ready to calculate the volume of 10.5 g of nitrogen dioxide gas. Click here to check your answer. |
