Question

1. ionic compounds containing polyatomic ions are named similarly to binary ionic compounds, except that the polyatomic ion name is used whenever one is encountered. caco₃ calcium carbonate naclo₃ nahco₃ k₂cro₄ nh₄cl mgso₄ kno₃ ca(oh)₂ al₂(cr₂o₇)₃ be(mno₄)₂ 4. writing formulas for ionic compounds containing polyatomic ions is accomplished in the same manner that it is for binary ionic compounds. the difference is that parenthesis must be used with polyatomic ions needing subscripts. in the above problem, the (mno₄)₂ means that there are two mno₄⁻ ions in the compound. trying to write the compound formula without the parenthesis, bemno₄₂, would suggest that the compound contains 42 oxygen atoms. aluminum nitrate calcium sulfate lithium cyanide magnesium phosphate potassium chlorate

Explanation:

Step1: Identify poly - atomic ions

For naming ionic compounds with poly - atomic ions, we use the name of the poly - atomic ion.

Step2: Name compounds

• $NaClO_3$: Sodium is the cation and $ClO_3^-$ is chlorate ion, so it is sodium chlorate.
• $NaHCO_3$: Sodium is the cation and $HCO_3^-$ is hydrogen carbonate (bicarbonate) ion, so it is sodium hydrogen carbonate (sodium bicarbonate).
• $K_2CrO_4$: Potassium is the cation and $CrO_4^{2 - }$ is chromate ion, so it is potassium chromate.
• $NH_4Cl$: $NH_4^+$ is ammonium ion and $Cl^-$ is chloride ion, so it is ammonium chloride.
• $MgSO_4$: Magnesium is the cation and $SO_4^{2 - }$ is sulfate ion, so it is magnesium sulfate.
• $KNO_3$: Potassium is the cation and $NO_3^-$ is nitrate ion, so it is potassium nitrate.
• $Ca(OH)_2$: Calcium is the cation and $OH^-$ is hydroxide ion, so it is calcium hydroxide.
• $Al_2(Cr_2O_7)_3$: Aluminum is the cation and $Cr_2O_7^{2 - }$ is dichromate ion, so it is aluminum dichromate.
• $Be(MnO_4)_2$: Beryllium is the cation and $MnO_4^-$ is permanganate ion, so it is beryllium permanganate.
• Aluminum nitrate: Aluminum has a + 3 charge ($Al^{3+}$) and nitrate is $NO_3^-$, so the formula is $Al(NO_3)_3$.
• Calcium sulfate: Calcium has a + 2 charge ($Ca^{2+}$) and sulfate is $SO_4^{2 - }$, so the formula is $CaSO_4$.
• Lithium cyanide: Lithium has a + 1 charge ($Li^+$) and cyanide is $CN^-$, so the formula is $LiCN$.
• Magnesium phosphate: Magnesium has a + 2 charge ($Mg^{2+}$) and phosphate is $PO_4^{3 - }$. To balance the charges, the formula is $Mg_3(PO_4)_2$.
• Potassium chlorate: Potassium has a + 1 charge ($K^+$) and chlorate is $ClO_3^-$, so the formula is $KClO_3$.

Answer:

$NaClO_3$: sodium chlorate
$NaHCO_3$: sodium hydrogen carbonate (sodium bicarbonate)
$K_2CrO_4$: potassium chromate
$NH_4Cl$: ammonium chloride
$MgSO_4$: magnesium sulfate
$KNO_3$: potassium nitrate
$Ca(OH)_2$: calcium hydroxide
$Al_2(Cr_2O_7)_3$: aluminum dichromate
$Be(MnO_4)_2$: beryllium permanganate
Aluminum nitrate: $Al(NO_3)_3$
Calcium sulfate: $CaSO_4$
Lithium cyanide: $LiCN$
Magnesium phosphate: $Mg_3(PO_4)_2$
Potassium chlorate: $KClO_3$