Professional Courses
Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Categories
Interactive Games
Fun, engaging games to boost memory, math fluency, typing speed, and English skills—perfect for learners of all ages.
Typing
Memory
Math
English Adventures
Knowledge
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Practice Questions
Test your understanding with targeted questions related to the topic.
Question 1
Easy
Calculate the number of moles in 20.0 g of potassium (K). (Molar mass = 39.10 g/mol)
💡 Hint: Use the formula: moles = mass ÷ molar mass.
Question 2
Easy
How many grams are in 3.5 moles of carbon dioxide (CO₂)? (Molar mass = 44.01 g/mol)
💡 Hint: Apply mass = moles × molar mass.
Practice 4 more questions and get performance evaluation
Interactive Quizzes
Engage in quick quizzes to reinforce what you've learned and check your comprehension.
Question 1
What is the molar mass of water (H₂O)?
- 18.02 g/mol
- 16.00 g/mol
- 20.01 g/mol
💡 Hint: Remember to sum the masses of all atoms in the molecule.
Question 2
True or False: Avogadro's number is 6.02214076 × 10²³.
- True
- False
💡 Hint: Think about how Avogadro's number relates to counting molecules in a mole.
Solve 1 more question and get performance evaluation
Challenge Problems
Push your limits with challenges.
Question 1
You have a sample of nitrogen gas (N₂) weighing 30.0 g. Calculate the number of moles and molecules present.
💡 Hint: Use the molar mass for conversion and Avogadro’s number to find the number of molecules.
Question 2
You have 2.00 moles of sodium chloride (NaCl). Calculate the total mass and the number of formula units.
💡 Hint: Find the molar mass first, then use it to find total mass and apply Avogadro's number for the unit calculation.
Challenge and get performance evaluation