Answer (score: #): 10. Select two compounds in which phosphorus has an oxidation state+5 5 CaHPO_(4) 1) Ca_(3)P_(2) 2) P_(4) 3) PBr_(5) 4) PH_(3) Answer (score: 1):

To determine the oxidation state of phosphorus in each compound, we need to consider the typical oxidation states of the other elements in the compound and the fact that the compound as a whole is neutral.<br /><br />1) In $Ca_{3}P_{2}$, phosphorus is in the -3 oxidation state. This is because calcium (Ca) typically has an oxidation state of +2, and there are three calcium atoms for every two phosphorus atoms.<br /><br />2) In $P_{4}$, phosphorus is in the 0 oxidation state. This is because there are no other elements in the compound, so the oxidation state of phosphorus is 0.<br /><br />3) In $PBr_{5}$, phosphorus is in the +5 oxidation state. This is because bromine (Br) typically has an oxidation state of -1, and there are five bromine atoms for every one phosphorus atom.<br /><br />4) In $PH_{3}$, phosphorus is in the -3 oxidation state. This is because hydrogen (H) typically has an oxidation state of +1, and there are three hydrogen atoms for every one phosphorus atom.<br /><br />Therefore, the two compounds in which phosphorus has an oxidation state of +5 are $PBr_{5}$ and $CaHPO_{4}$.