Question

fill in the name and empirical formula of each ionic compound that could be formed from the ions in this table:
some ionic compounds
cation anion empirical formula name of compound
cr²⁺ cn⁻
k⁺ bro₃⁻
na⁺ po₄³⁻

Explanation:

Step1: Determine formula for $Cr^{2 +}$ and $CN^{-}$

The charges must balance. For $Cr^{2+}$ and $CN^{-}$, we need 2 $CN^{-}$ ions to balance the + 2 charge of $Cr^{2+}$. So the empirical formula is $Cr(CN)_2$. The name is chromium(II) cyanide as chromium has a + 2 oxidation - state.

Step2: Determine formula for $K^{+}$ and $BrO_{3}^{-}$

The charges of $K^{+}$ and $BrO_{3}^{-}$ are already balanced. So the empirical formula is $KBrO_{3}$. The name is potassium bromate.

Step3: Determine formula for $Na^{+}$ and $PO_{4}^{3 -}$

We need 3 $Na^{+}$ ions to balance the - 3 charge of $PO_{4}^{3-}$. So the empirical formula is $Na_{3}PO_{4}$. The name is sodium phosphate.

Answer:

cation	anion	empirical formula	name of compound
$K^{+}$	$BrO_{3}^{-}$	$KBrO_{3}$	potassium bromate
$Na^{+}$	$PO_{4}^{3 -}$	$Na_{3}PO_{4}$	sodium phosphate