Question

practice: balance and rewrite the following chemical equations

1. $agno_{3}+h_{2}s\to ag_{2}s+hno_{3}$
2. $zn(oh)_{2}+h_{3}po_{4}\to zn_{3}(po_{4})_{2}+h_{2}o$
3. $cu(s)+agno_{3}(aq)\to cu(no_{3})_{2}(aq)+ag(s)$
4. $al(s)+o_{2}(g)\to al_{2}o_{3}(s)$
5. $fecl_{3}+naoh\to fe(oh)_{3}+nacl$
6. $cs_{2}+cl_{2}\to ccl_{4}+s_{2}cl_{2}$

Explanation:

Step1: Balance equation 5

• Balance Ag atoms: Put 2 in front of \(AgNO_3\)

\(2AgNO_3 + H_2S
ightarrow Ag_2S + HNO_3\)

• Balance \(NO_3\) groups: Put 2 in front of \(HNO_3\)

\(2AgNO_3 + H_2S = Ag_2S + 2HNO_3\)

Step2: Balance equation 6

• Balance Zn atoms: Put 3 in front of \(Zn(OH)_2\)

\(3Zn(OH)_2 + H_3PO_4
ightarrow Zn_3(PO_4)_2 + H_2O\)

• Balance \(PO_4\) groups: Put 2 in front of \(H_3PO_4\)

\(3Zn(OH)_2 + 2H_3PO_4
ightarrow Zn_3(PO_4)_2 + H_2O\)

• Balance H and O atoms: Put 6 in front of \(H_2O\)

\(3Zn(OH)_2 + 2H_3PO_4 = Zn_3(PO_4)_2 + 6H_2O\)

Step3: Balance equation 7

• Balance Ag atoms: Put 2 in front of \(AgNO_3\) and \(Ag\)

\(Cu(s)+2AgNO_3(aq)
ightarrow Cu(NO_3)_2(aq)+2Ag(s)\)

Step4: Balance equation 8

• Balance O atoms: Put 3 in front of \(O_2\) and 2 in front of \(Al_2O_3\)

\(Al(s)+3O_2(g)
ightarrow 2Al_2O_3(s)\)

• Balance Al atoms: Put 4 in front of \(Al\)

\(4Al(s)+3O_2(g)=2Al_2O_3(s)\)

Step5: Balance equation 9

• Balance Fe atoms: Already balanced.
• Balance Cl atoms: Put 3 in front of \(NaCl\)

\(FeCl_3 + NaOH
ightarrow Fe(OH)_3 + 3NaCl\)

• Balance Na and O atoms: Put 3 in front of \(NaOH\)

\(FeCl_3 + 3NaOH = Fe(OH)_3 + 3NaCl\)

Step6: Balance equation 10

• Balance C atoms: Already balanced.
• Balance S atoms: Put 2 in front of \(S_2Cl_2\)

\(CS_2+Cl_2
ightarrow CCl_4 + 2S_2Cl_2\)

• Balance Cl atoms: Put 4 in front of \(Cl_2\)

\(CS_2 + 4Cl_2 = CCl_4 + 2S_2Cl_2\)

Answer:

1. \(2AgNO_3 + H_2S = Ag_2S + 2HNO_3\)
2. \(3Zn(OH)_2 + 2H_3PO_4 = Zn_3(PO_4)_2 + 6H_2O\)
3. \(Cu(s)+2AgNO_3(aq)=Cu(NO_3)_2(aq)+2Ag(s)\)
4. \(4Al(s)+3O_2(g)=2Al_2O_3(s)\)
5. \(FeCl_3 + 3NaOH = Fe(OH)_3 + 3NaCl\)
6. \(CS_2 + 4Cl_2 = CCl_4 + 2S_2Cl_2\)