Write a formula for the compound that forms between rubidium and each polyatomic ion: Part A Carbonate. Express your answer as a chemical formula. Part B Phosphate. Express your answer as a chemical formula. Part C Hydrogen phosphate. Express your answer as a chemical formula. Part D Acetate. Express your answer as a chemical formula.
The Correct Answer and Explanation is:
Part A: Rubidium Carbonate
The formula for rubidium carbonate can be determined by looking at the charges on the ions involved.
- Rubidium (Rb) is an alkali metal, and its ion is Rb+Rb^+Rb+.
- Carbonate (CO32−CO_3^{2-}CO32−) has a charge of 2−2-2−.
To balance the charges, two Rb+Rb^+Rb+ ions are needed for each CO32−CO_3^{2-}CO32− ion. Therefore, the formula is:Rb2CO3\text{Rb}_2\text{CO}_3Rb2CO3
Part B: Rubidium Phosphate
Phosphate ions (PO43−PO_4^{3-}PO43−) have a charge of 3−3-3−, while rubidium ions (Rb+Rb^+Rb+) have a charge of 1+1+1+. To balance the charges, three Rb+Rb^+Rb+ ions are needed for each PO43−PO_4^{3-}PO43− ion. Thus, the formula for rubidium phosphate is:Rb3PO4\text{Rb}_3\text{PO}_4Rb3PO4
Part C: Rubidium Hydrogen Phosphate
Hydrogen phosphate (HPO42−HPO_4^{2-}HPO42−) has a charge of 2−2-2−, while rubidium has a charge of 1+1+1+. To balance the charges, two Rb+Rb^+Rb+ ions are needed for each HPO42−HPO_4^{2-}HPO42− ion. Thus, the formula for rubidium hydrogen phosphate is:Rb2HPO4\text{Rb}_2\text{HPO}_4Rb2HPO4
Part D: Rubidium Acetate
Acetate (C2H3O2−C_2H_3O_2^-C2H3O2−) has a charge of 1−1-1−, while rubidium (Rb+Rb^+Rb+) has a charge of 1+1+1+. Since the charges are equal and opposite, one Rb+Rb^+Rb+ ion will balance one acetate ion. Therefore, the formula for rubidium acetate is:RbC2H3O2\text{RbC}_2\text{H}_3\text{O}_2RbC2H3O2
In summary:
- Part A: Rb2CO3\text{Rb}_2\text{CO}_3Rb2CO3
- Part B: Rb3PO4\text{Rb}_3\text{PO}_4Rb3PO4
- Part C: Rb2HPO4\text{Rb}_2\text{HPO}_4Rb2HPO4
- Part D: RbC2H3O2\text{RbC}_2\text{H}_3\text{O}_2RbC2H3O2
The formulas are derived by ensuring the positive and negative charges are balanced, with the number of each ion adjusted accordingly.
