Answer:
[tex]NO_2[/tex] and [tex]La_2O_7[/tex]
Explanation:
Nitrogen:
[tex]\frac{42.05}{14}=3[/tex]
Oxygen:
[tex]\frac{95.95}{16}=6[/tex]
Ratio:
[tex]3:6=1:2[/tex]
So empirical formula becomes [tex]NO_2[/tex]
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Lanthanum:
[tex]\frac{7.33}{139}=0.0527[/tex]
Oxygen:
[tex]\frac{2.96}{16}=0.185[/tex]
Ratio:
[tex]0.0527:0.185=1:3.5=2:7[/tex]
So empirical formula becomes [tex]La_2O_7[/tex]
