This video tutorial covers the practice unit exam on mole ratios, stoichiometry, and types of chemical reactions. It explains the difference between molecular and empirical formulas, using hydrocarbons as an example. The video also demonstrates how to calculate molecular mass and gram formula mass for various compounds, emphasizing the importance of understanding these concepts in chemistry.

What is the main topic of the video series?

• Thermodynamics

• Periodic Table and Atomic Structure

• Mole Ratios, Stoichiometry, and Types of Chemical Reactions

• Acids and Bases

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

What elements are present in hydrocarbons?

• Hydrogen and Carbon

• Hydrogen and Oxygen

• Carbon and Nitrogen

• Carbon and Oxygen

What is the empirical formula of a compound with a molecular formula of C5H10?

• C3H6

• C2H5

• CH2

• C5H10

Which of the following pairs correctly matches a molecular formula with its empirical formula?

• C6H12 and CH2

• C4H10 and C2H5

• C3H6 and CH3

• C2H4 and CH2

What is the first step in determining the molecular formula from an empirical formula and molecular mass?

• Calculate the mass of the empirical formula

• Double the empirical formula

• Find the number of atoms

• Divide the molecular mass by the empirical formula mass

If the empirical formula is C2H3 and the molecular mass is 54, what is the molecular formula?

• C8H12

• C6H9

• C4H6

• C2H3

What is the gram formula mass of Ca3(PO4)2?

• 320 grams per mole

• 330 grams per mole

• 310 grams per mole

• 340 grams per mole

How many moles of oxygen are in Ca3(PO4)2?

• 4

• 6

• 8

• 10

What is the mass of one mole of nitrogen in NH4Cl?

• 18 grams

• 12 grams

• 14 grams

• 16 grams

What is the total gram formula mass of NH4Cl?

• 51 grams per mole

• 54 grams per mole

• 52 grams per mole

• 53 grams per mole