1. Need help Assigning oxidation numbers. Is it true that wehn looking at atoms in compounds from group 1 or 2 they are given the oxidization number which is the same as there charge example NaCl Na has an oxidization number of 1?
But is this also true for atoms in compounds which are from the 17 group exammple cacl2 cl has an oxidization number of -1 because it is found in the 17th group.
2. If a compound is given in which neither oxidization number is known is there charge automatically assighned exampple CN^- thank you.
Elements in Group 1 are assigned an oxidation number of 1. That is the same as the electrical charge on ions formed frm that group.
Elements in Group 17 (or Group VII-A) form ions with an electrical charge of -1. That is also their oxidation number in BINARY compounds like NaCl, SrBr2, etc.
In tertiary compounds like KClO3, NaOBr, etc., the Group 17 element is NOT assigned an oxidation number. That is calculated from the assigned oxidation numbers of the other two elements.
Finally, remember that elements in their "free" state are assigned an oxidation number of 0. In a formula of a compound like BaSO4, the sum of all the oxidation numbers is 0. In a polyatomic ion, the sum of the oxidation numbers is the ionic charge.
In simple monoatomic (1 atom) ions like Al^3+, Ba^2+, S^2-, etc., the oxidation number is the same as the electrical charge.
thanks
1. When assigning oxidation numbers, it's important to understand that oxidation numbers represent the hypothetical charge that an atom would have if electrons were completely transferred in a compound. In general, for elements in Group 1 (e.g., Na) or Group 2 (e.g., Ca), the oxidation number is typically equal to their charge. For example, NaCl would have Na with an oxidation number of +1 due to being in Group 1 and Cl with an oxidation number of -1 because it generally takes on a -1 charge in compounds.
However, when dealing with elements in Group 17 (e.g., Cl), such as in CaCl2, the oxidation number is not automatically -1. The oxidation number for Cl in CaCl2 can be determined by considering the known oxidation number of Ca (which is typically +2) and applying the principle that the sum of oxidation numbers in a neutral compound is zero. Since there are two Cl atoms in CaCl2, the total oxidation number of Cl must be -2 to balance out the +2 oxidation number of Ca. Therefore, each Cl atom in CaCl2 has an oxidation number of -1.
2. In cases where the oxidation numbers of individual elements in a compound are not known, but you know the overall charge on the compound, you can use this information to assign the oxidation numbers. For example, in the compound CN^-, the overall charge is -1. The oxidation number of the CN^- compound is determined by balancing the oxidation numbers to equal the overall charge. Since nitrogen (N) is more electronegative than carbon (C), it is common to assign the oxidation number of -3 to nitrogen and +3 to carbon in this compound.
Remember, assigning oxidation numbers is a way to keep track of electron transfer in a compound, and it follows certain rules and patterns. It's always essential to consider the properties of the elements and the overall charge of the compound to accurately assign oxidation numbers.