Practice Empirical and Molecular Formulas - 1.2 | Chapter 1: Stoichiometric Relationships | IB 12 Chemistry
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Empirical and Molecular Formulas

1.2 - Empirical and Molecular Formulas

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Practice Questions

Test your understanding with targeted questions

Question 1 Easy

What is the empirical formula?

💡 Hint: Think of it as the reduced form of the chemical formula.

Question 2 Easy

What does the molecular formula tell us?

💡 Hint: It's a complete version, unlike the empirical one.

4 more questions available

Interactive Quizzes

Quick quizzes to reinforce your learning

Question 1

What is the ratio of elements in an empirical formula?

Actual number of atoms
Simplest whole number ratio
Mass of elements

💡 Hint: Think of it as a simplified version of a chemical formula.

Question 2

True or False: The molecular formula can be exactly the same as the empirical formula.

True
False

💡 Hint: Consider compounds where elements have the same ratios.

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Challenge Problems

Push your limits with advanced challenges

Challenge 1 Hard

A compound is found to contain 35.0% Carbon, 7.0% Hydrogen, and 58.0% Oxygen by mass. Calculate both the empirical and molecular formulas given the molar mass is 180 g/mol.

💡 Hint: Convert mass percentages to moles, find ratios, then apply molar mass.

Challenge 2 Hard

Given a compound composed of 10.0 g of Nitrogen and 30.0 g of Oxygen, find the empirical and molecular formulas given its molar mass of 90 g/mol.

💡 Hint: Use the masses to find moles, then ratios to find empirical, followed by molar mass for molecular.

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Reference links

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