Combined for unit 6A

What percent of Zn₃(PO₄)₂ is zinc?

• 33.15%
• 16.04%
• 50.81%
• 19.68%

What is the empirical formula if you have 36.84% nitrogen and 63.16% oxygen?

• NO
• N₂O₃
• N₂O₄
• N₂O₅

An empirical formula:

• is a formula that calculates the coefficients of a compound in a balanced equation.
• is the simplest whole-number ratio of moles of elements in the compound.

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

A chemical formula that shows the actual # and kinds of atoms present in one molecule of a compound is called_________

• ionic formula
• covalent formula
• empirical formula
• molecular formula

What is oxidation number of H in H₂O?

• 0
• -2
• -1
• +1

What is oxidation number of O in K₃PO₄?

• +1

• +5

• -2

• 0

What is oxidation number of H in HCl?

• +1

• -1

• 0

• +2

What is oxidation number of Fe in FeO ?

• +2
• -2
• 0
• +1

What is oxidation number of Ca in CaCl₂ ?

• -1
• -2
• +1
• +2