Question

-make sure that the change of the compound equals zero.

1. $\stackrel{+3}{\text{al}}$ & $\stackrel{-2}{\text{o}}$
2. sr & s
3. li & cl
4. ca & $\text{so}_4^{2-}$
5. k & $\text{po}_4^{3-}$
6. al & $\text{no}_3^-$
7. mg & $\text{c}_2\text{h}_3\text{o}_2^-$
8. ca & $\text{cn}^-$

predict, balance, and classify the following ch

1. cu + $\text{feso}_4$ $\

ightarrow$

1. $2\text{k}$ + $2\text{agno}_3$ $\

ightarrow$

Explanation:

Step1: Fix Al & O formula

Al has +3 charge, O has -2 charge. Use crisscross method: $\text{Al}_2\text{O}_3$

Step2: Fix Sr & S formula

Sr has +2 charge, S has -2 charge. Simplify ratio: $\text{SrS}$

Step3: Confirm Li & Cl formula

Li has +1 charge, Cl has -1 charge: $\text{LiCl}$

Step4: Fix Ca & $\text{SO}_4^{2-}$ formula

Ca has +2 charge, $\text{SO}_4^{2-}$ has -2 charge: $\text{CaSO}_4$

Step5: Confirm K & $\text{PO}_4^{3-}$ formula

K has +1 charge, $\text{PO}_4^{3-}$ has -3 charge: $\text{K}_3\text{PO}_4$

Step6: Find Al & $\text{NO}_3^-$ formula

Al has +3 charge, $\text{NO}_3^-$ has -1 charge. Crisscross: $\text{Al(NO}_3\text{)}_3$

Step7: Find Mg & $\text{C}_2\text{H}_3\text{O}_2^-$ formula

Mg has +2 charge, $\text{C}_2\text{H}_3\text{O}_2^-$ has -1 charge. Crisscross: $\text{Mg(C}_2\text{H}_3\text{O}_2\text{)}_2$

Step8: Find Ca & $\text{CN}^-$ formula

Ca has +2 charge, $\text{CN}^-$ has -1 charge. Crisscross: $\text{Ca(CN)}_2$

Step9: Analyze Cu + $\text{FeSO}_4$ reaction

Cu is less reactive than Fe, so no reaction: $\text{Cu} + \text{FeSO}_4
ightarrow \text{No Reaction}$

Step10: Balance K + $\text{AgNO}_3$ reaction

K has +1, $\text{AgNO}_3$ has $\text{Ag}^+$; products are $\text{KNO}_3$ and Ag. Balanced: $2\text{K} + 2\text{AgNO}_3
ightarrow 2\text{KNO}_3 + 2\text{Ag}$

Answer:

1. $\text{Al}_2\text{O}_3$
2. $\text{SrS}$
3. $\text{LiCl}$
4. $\text{CaSO}_4$
5. $\text{K}_3\text{PO}_4$
6. $\text{Al(NO}_3\text{)}_3$
7. $\text{Mg(C}_2\text{H}_3\text{O}_2\text{)}_2$
8. $\text{Ca(CN)}_2$
9. $\text{Cu} + \text{FeSO}_4

ightarrow \text{No Reaction}$ (single displacement, non-spontaneous)

1. $2\text{K} + 2\text{AgNO}_3

ightarrow 2\text{KNO}_3 + 2\text{Ag}$ (single displacement, spontaneous)