Question

1. what is the formula for iron (iii) bromide?febrfebr₂febr₃fe₃br17. what is the formula for calcium sulfide?casca₂scas₂ca₂s₂18. what is the formula for phosphorus trichloride?pclpcl₂pcl₃p₃cl₃19. what is the formula for dicarbon hexafluoride?c₂f₆c₂f₄cf₆c₆f₂20. what is the name for (no₂)⁻?nitritenitrateammoniumnitride21. what is the name for mg₃n₂?magnesium nitridemagnesium nitratetrimagnesium nitridemagnesium dinitride22. what is the name for bacl₂?barium dichloridebarium chloridebarium chloratemonobarium chloride23. what is the name for n₂o₅?dinitrogen pentoxidenitrogen oxidepentanitrogen dioxidenitrogen peroxide24. what is the name for so₃?sulfur monoxidesulfur trioxidetrisulfur oxidesodium oxide

Explanation:

Step1: Determine iron(III) bromide formula

Iron(III) has charge $\text{Fe}^{3+}$, bromide is $\text{Br}^-$. Balance charges: $3+ + 3(-1)=0$, so formula is $\text{FeBr}_3$.

Step2: Confirm calcium sulfide formula

Calcium is $\text{Ca}^{2+}$, sulfide is $\text{S}^{2-}$. Balance charges: $2+ + 2-=0$, so formula is $\text{CaS}$.

Step3: Find phosphorus trichloride formula

Prefix "tri-" means 3 chlorines. Phosphorus is $\text{P}$, chlorine is $\text{Cl}$, so formula is $\text{PCl}_3$.

Step4: Dicarbon hexafluoride formula

Prefixes "di-" (2 C) and "hexa-" (6 F), so formula is $\text{C}_2\text{F}_6$.

Step5: Name $\text{NO}_3^-$ ion

$\text{NO}_3^-$ is the nitrate polyatomic ion.

Step6: Name $\text{Mg}_3\text{N}_2$

Magnesium is $\text{Mg}^{2+}$, nitride is $\text{N}^{3-}$. Use ionic naming: Magnesium nitride.

Step7: Name $\text{BaCl}_2$

Barium is $\text{Ba}^{2+}$, chloride is $\text{Cl}^-$. Ionic naming omits "di-" for common salts: Barium chloride.

Step8: Name $\text{N}_2\text{O}_5$

Covalent naming: "di-" (2 N) and "pentoxide" (5 O): Dinitrogen pentoxide.

Step9: Name $\text{SO}_3$

Covalent naming: "trioxide" (3 O): Sulfur trioxide.

Answer:

1. $\text{FeBr}_3$
2. $\text{CaS}$
3. $\text{PCl}_3$
4. $\text{C}_2\text{F}_6$
5. Nitrate
6. Magnesium nitride
7. Barium chloride
8. Dinitrogen pentoxide
9. Sulfur trioxide