- Tin, Sn, commonly forms two cations: tin(II), Sn2+; and tin(IV), Sn4+. Oxygen is a Group VIA element. It is a member of the chalcogen family a. What charge does the oxide (oxygen) anion form? b. Give the formula of two ionic compounds that can form when the two cations of tin (from above) combine with the anion of oxygen.
The Correct Answer and Explanation is:
a. What charge does the oxide (oxygen) anion form?
Oxygen typically forms an anion with a –2 charge, written as O²⁻.
b. Give the formula of two ionic compounds that can form when the two cations of tin (from above) combine with the anion of oxygen.
- Tin(II) oxide: SnO
- Tin(IV) oxide: SnO₂
Explanation :
Tin (Sn), a post-transition metal, commonly forms two oxidation states: +2 and +4. These cations are known as tin(II), represented as Sn²⁺, and tin(IV), represented as Sn⁴⁺. These cations differ in their electron loss, with Sn²⁺ losing two electrons and Sn⁴⁺ losing four. Tin forms ionic compounds with nonmetals, such as oxygen, by transferring electrons to them.
Oxygen is a Group VIA (Group 16) element and part of the chalcogen family. It has six valence electrons and needs two more electrons to complete its octet. Therefore, oxygen typically gains two electrons to form the oxide ion, O²⁻, which has a –2 charge.
When tin ions combine with oxide ions, they form ionic compounds based on the need to balance the total positive and negative charges:
- Tin(II) oxide (SnO):
- The Sn²⁺ cation has a +2 charge.
- The O²⁻ anion has a –2 charge.
- One Sn²⁺ ion balances one O²⁻ ion.
- Thus, the empirical formula is SnO.
- Tin(IV) oxide (SnO₂):
- The Sn⁴⁺ cation has a +4 charge.
- Each O²⁻ anion has a –2 charge.
- Two O²⁻ ions (total –4) are needed to balance one Sn⁴⁺ ion.
- The formula becomes SnO₂.
These compounds are examples of how metals and nonmetals form stable ionic compounds through electron transfer and charge balancing. The subscripts in chemical formulas reflect the ratio needed to ensure the overall charge is neutral. Tin’s ability to form multiple cations leads to different compounds with different chemical and physical properties.
