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1. The Chemical World9m
- The Scientific Method
  9m
2. Measurement and Problem Solving2h 19m
3. Matter and Energy2h 15m
4. Atoms and Elements2h 33m
5. Molecules and Compounds1h 50m
6. Chemical Composition1h 23m
7. Chemical Reactions1h 43m
8. Quantities in Chemical Reactions1h 8m
9. Electrons in Atoms and the Periodic Table2h 32m
10. Chemical Bonding2h 10m
11 Gases2h 7m
12. Liquids, Solids, and Intermolecular Forces1h 11m
13. Solutions3h 1m
14. Acids and Bases2h 14m
15. Chemical Equilibrium1h 27m
16. Oxidation and Reduction1h 33m
17. Radioactivity and Nuclear Chemistry53m

5. Molecules and Compounds

Writing Formula Units of Ionic Compounds

Introduction to Chemistry

5. Molecules and Compounds

Writing Formula Units of Ionic Compounds

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Multiple Choice

Provide the molecular formula for the following compound:Sodium dichromate

NaCr₂O₇

Na(Cr₂O₇)₂

NaCrO₄

Na₂Cr₂O₇

Na₂CrO₄

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Identify the elements present in sodium dichromate: sodium (Na), chromium (Cr), and oxygen (O).

Understand that sodium dichromate is a compound where sodium ions are combined with the dichromate ion (Cr2O7^2-).

Recognize that the dichromate ion (Cr2O7^2-) consists of two chromium atoms and seven oxygen atoms.

Determine the charge balance: Sodium ions (Na^+) have a +1 charge, and the dichromate ion (Cr2O7^2-) has a -2 charge. To balance the charges, two sodium ions are needed for one dichromate ion.

Combine the elements and their respective quantities to form the molecular formula: Na2Cr2O7, which includes two sodium atoms, two chromium atoms, and seven oxygen atoms.