Question

1. choose the pair of names and formulas that do not match. a) calcium carbonate: caco₃ b) sodium hydrogen carbonate: nahco₃ c) magnesium nitrite: mg(no₂)₃ d) aluminum sulfate: (nh₄)₂so₄ e) potassium hydroxide: koh 49) what is the name of hio₃? a) iodous acid b) iodic acid c) hydroiodous acid d) hydroioidic acid e) none of the above 50) what would the formula of diiodine pentasulfide be? a) i₅s₂ b) i₂s₅ c) i₂s₇ d) i₄s₉ e) none of the above

Explanation:

Step1: Analyze question 48

Check each compound - name and formula pair. Calcium carbonate is $CaCO_3$, sodium hydrogen carbonate is $NaHCO_3$, magnesium nitrite is $Mg(NO_2)_2$, aluminum sulfate is $Al_2(SO_4)_3$, potassium hydroxide is $KOH$. $(NH_4)_2SO_4$ is ammonium sulfate not potassium sulfate.

Step2: Analyze question 49

$HIO_3$ is an oxy - acid. The name of an oxy - acid with the central atom in its common oxidation state is named as the root of the central atom + ic + acid. For $HIO_3$, the central atom is iodine, so it is iodic acid.

Step3: Analyze question 50

The prefixes in the name of a binary covalent compound indicate the number of atoms of each element. Di - means 2 for iodine and penta - means 5 for sulfur. So the formula of diiodine pentasulfide is $I_2S_5$.

Answer:

1. E. Potassium sulfate: $(NH_4)_2SO_4$
2. B. iodic acid
3. B. $I_2S_5$