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Home Concept Builders Stoichiometry Limiting Reactants Directions

Limiting Reactants - Directions

Using the Limiting Reactants Concept Builder is quite simple. You will be presented with a balanced chemical equation and a table into which you must enter your answers. Depending upon the activity, you will either need to enter the number of moles (first and second activity) or the mass in grams (third activity) into the table cell. The table field begins with a grey background color. You can enter your answer directly into the field from the keyboard. If you are using a touch screen device or mobile device you may prefer to use our built-in number pad that does not cover any portion of the table. To use our number pad, tap on the number pad icon to the right of the table cell; a number pad slides onto the screen along the right side. It can be used to enter or edit your answer. The active editing field will have a yellow background color; numbers will be entered into that field. You can tap on a different field's number pad icon to enter numbers into that field.

You can tap on the Check Answers button at any time. All fields with entries will be checked for accuracy and you will receive immediate feedback. If a field has the correct value, then it will display a green background color and no longer be editable. If a field has an incorrect answer, then it will display a pink background color and can still be edited. There's no limit on the number of attempts. We advise entering answers to three significant digits and using molar mass values with at least three significant digits. Your answer must be within 2% of the keyed answer to be considered correct. For the second and third activities, there is a conceptual question that must be answered; you must identify the limiting reactant. The question shows up below the table. You can tap on the answer field to toggle through each answer option. Once your analysis is completed, the next question in the activity will be presented to you. A progress report is displayed at all times on the right side of the screen that shows how you are doing on the particular activity.

Concept Builder Teacher Notes