Question

write formulas for the compounds formed from sr and each of the following polyatomic ions: no2^-, co3^2-, po4^3-. express your answers as chemical formulas separated by commas.

Explanation:

Step1: Determine the charge of Sr ion

Strontium (Sr) is an alkaline earth metal, so it forms a \( \text{Sr}^{2+} \) ion (loses 2 electrons).

Step2: Combine with \( \text{NO}_2^- \)

To balance the charges, we need 2 \( \text{NO}_2^- \) ions for each \( \text{Sr}^{2+} \) ion (since \( 2\times(-1)+(+2) = 0 \)). So the formula is \( \text{Sr(NO}_2\text{)}_2 \).

Step3: Combine with \( \text{CO}_3^{2-} \)

The charge of \( \text{Sr}^{2+} \) and \( \text{CO}_3^{2-} \) are +2 and -2 respectively. The ratio is 1:1 (since \( (+2)+(-2)=0 \)). So the formula is \( \text{SrCO}_3 \).

Step4: Combine with \( \text{PO}_4^{3-} \)

Let the number of \( \text{Sr}^{2+} \) be \( x \) and \( \text{PO}_4^{3-} \) be \( y \). We have \( 2x - 3y=0 \), so \( x:y = 3:2 \). Thus the formula is \( \text{Sr}_3(\text{PO}_4)_2 \).

Answer:

\( \text{Sr(NO}_2\text{)}_2, \text{SrCO}_3, \text{Sr}_3(\text{PO}_4)_2 \)