NTW empirical formula 1 and 2-1 PDF

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NTW – Empirical Formulas Videos 1 & 2 Define Molecular Formula. Provide an example of a Molecular Formula. Define Empirical Formula. Provide the empirical formula that relates to the molecular formula you wrote above. What do you need to calculate first when calculating the empirical formula? Practice: A certain compound is 52.2% Carbon, 13.0% hydrogen, and 34.8% oxygen. Find the empirical formula of the compound. The prompts that follow correspond to the information entered into the table. You may want to draw out the table as well. Write down your elements. Record the molar masses of the elements in your compound. Explain why you need this value. What are the units for this value? Record the mass of each of the elements in your compound. Explain where these values came from. What made this quick conversion possible? How do you calculate the moles of a substance? Perform those calculations. How do you calculate the mole ratio? Why do you perform this calculation? Explain what the mole ratio means in terms of molecules relating to each other. What is the difference between the mole ratio and the formula ratio? What is the empirical formula of this compound? What are some scenarios where you can’t just round the mole ratio to determine the formula ratio? Explain the steps you need to take to remedy this problem. Why does this procedure work? It may help to write out the summary of the steps to calculate the empirical formula. Practice: A sample of an oxide of arsenic is found to contain 75.74% arsenic. What is its empirical formula? Follow the prompts above to fill out an empirical formula table. There are some additional questions that follow that you should be able to answer. How were you able to determine the elements in the compound? How do you determine the percentage of an element if it is not given in the problem?

What extra step did you have to take to move from the mole ratio to the formula ratio in this example?

NTW – Molecular Formulas Videos 1 & 2 Define Empirical Formula again. Define Molecular Formula again. How are the empirical and molecular formulas related? Follow along with the NO and N2O2 example. How are these two compounds related? How do you express the relationship between these two formulas mathematically? Do the math to prove that there are two NO formula units in one N 2O2 molecule. Write this out in a sentence. Practice: Many compounds have the empirical formula of CH2O. The molar mass of one of these is 180.0 g/mol. Determine the molecular formula for this compound. What is your given quantity? What is your wanted quantity? What does your unit path look like? What piece do you need to calculate first to calculate the number of empirical formula units? How do you use the number of empirical formula units to move from the empirical formula to the molecular formula? What is the molecular formula of this compound? Practice: Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Determine the empirical formula for this compound. Try to follow along without prompts. If you need a nudge, refer to the empirical formula NTW. Determine the molecular formula for this compound....