Question

question 11 (0.5 points)listenwhich of the following are named correctly? choose all that are correct.$ce{fe_{2}s_{3}}$iron trisulfide$ce{pcl_{5}}$phosphorus pentachloride$ce{caf_{2}}$calcium(ii) fluoride$ce{cl_{2}o_{5}}$dichlorine pentoxidequestion 12 (0.25 points)listenwhat is the identity of the ion with an electron configuration of $ce{kr 4d^{10}}$ and has a charge of +3?$ce{y^{3+}}$$ce{as^{3+}}$$ce{in^{3+}}$$ce{pd^{3+}}$

Explanation:

Question 11

Step1: Analyze $\text{Fe}_2\text{S}_3$ naming

Iron is a transition metal; $\text{Fe}^{3+}$ (iron(III)) and $\text{S}^{2-}$ (sulfide) form this compound. The correct name is iron(III) sulfide, not iron trisulfide.

Step2: Analyze $\text{PCl}_5$ naming

This is a covalent compound. P is phosphorus, 5 Cl atoms use "penta-", so phosphorus pentachloride is correct.

Step3: Analyze $\text{CaF}_2$ naming

Calcium is a group 2 metal with only +2 charge; no Roman numeral is needed. Correct name is calcium fluoride, not calcium(II) fluoride.

Step4: Analyze $\text{Cl}_2\text{O}_5$ naming

This is a covalent compound. 2 Cl = "dichlorine", 5 O = "pentoxide", so dichlorine pentoxide is correct.

Step1: Find neutral atom electron config

The ion has config $[\text{Kr}]4d^{10}$ and +3 charge. A +3 charge means 3 electrons were lost, so the neutral atom has $[\text{Kr}]4d^{10}5s^25p^1$.

Step2: Match to element

This electron configuration corresponds to indium (In, atomic number 49). When it loses 3 electrons, it forms $\text{In}^{3+}$ with the given configuration.

Answer:

• $\text{PCl}_5$: phosphorus pentachloride
• $\text{Cl}_2\text{O}_5$: dichlorine pentoxide

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Question 12