Question

1. ____ naoh → __ na₂o + ____ h₂o

	reactants	products
o
h

1. ____ al₂o₃ → __ al + ____ o₂

	reactants	products
o

1. ____ k₂co₃ → __ k₂o + ____ co₂

	reactants	products
c
o

1. ____ zn(oh)₂ → __ zno + ____ h₂o

	reactants	products
o
h

1. ____ ag₂o → __ ag + ____ o₂

	reactants	products
o

1. ____ ni(clo₃)₂ → __ nicl₂ + ____ o₂

	reactants	products
cl
o

1. ____ hcl → __ h₂ + ____ cl₂

	reactants	products
cl

Explanation:

Step 1: Balance Equation 7

• Reactants: NaOH has 1 Na, 1 O, 1 H.
• Products: \( Na_2O \) has 2 Na, 1 O; \( H_2O \) has 2 H, 1 O.
• To balance Na: Put 2 in front of NaOH. Now NaOH: 2 Na, 2 O, 2 H.
• Check O and H: \( Na_2O \) (1 O) + \( H_2O \) (1 O) = 2 O; \( H_2O \) has 2 H. So coefficients: 2 NaOH → 1 \( Na_2O \) + 1 \( H_2O \).
• Reactants (Na: 2, O: 2, H: 2); Products (Na: 2, O: 2, H: 2).

Step 2: Balance Equation 8

• Reactants: \( Al_2O_3 \) has 2 Al, 3 O.
• Products: Al (1 Al), \( O_2 \) (2 O).
• Balance Al: Put 2 in front of Al. Now Al: 2.
• Balance O: \( Al_2O_3 \) has 3 O, \( O_2 \) needs 3 O (but \( O_2 \) is diatomic). Multiply \( Al_2O_3 \) by 2 (4 Al, 6 O) and Al by 4, \( O_2 \) by 3. So 2 \( Al_2O_3 \) → 4 Al + 3 \( O_2 \).
• Reactants (Al: 4, O: 6); Products (Al: 4, O: 6).

Step 3: Balance Equation 9

• Reactants: \( K_2CO_3 \) has 2 K, 1 C, 3 O.
• Products: \( K_2O \) (2 K, 1 O), \( CO_2 \) (1 C, 2 O).
• K: 2 on both. C: 1 on both. O: 3 (1 + 2) on products. So coefficients: 1 \( K_2CO_3 \) → 1 \( K_2O \) + 1 \( CO_2 \).
• Reactants (K: 2, C: 1, O: 3); Products (K: 2, C: 1, O: 3).

Step 4: Balance Equation 10

• Reactants: \( Zn(OH)_2 \) has 1 Zn, 2 O, 2 H.
• Products: ZnO (1 Zn, 1 O), \( H_2O \) (2 H, 1 O).
• Zn: 1 on both. O: 2 (1 + 1) on products. H: 2 on both. So coefficients: 1 \( Zn(OH)_2 \) → 1 ZnO + 1 \( H_2O \).
• Reactants (Zn: 1, O: 2, H: 2); Products (Zn: 1, O: 2, H: 2).

Step 5: Balance Equation 11

• Reactants: \( Ag_2O \) has 2 Ag, 1 O.
• Products: Ag (1 Ag), \( O_2 \) (2 O).
• Balance Ag: Put 2 in front of Ag. Now Ag: 2.
• Balance O: \( Ag_2O \) has 1 O, \( O_2 \) needs 2 O. Multiply \( Ag_2O \) by 2 (4 Ag, 2 O) and Ag by 4, \( O_2 \) by 1. So 2 \( Ag_2O \) → 4 Ag + 1 \( O_2 \).
• Reactants (Ag: 4, O: 2); Products (Ag: 4, O: 2).

Step 6: Balance Equation 12

• Reactants: \( Ni(ClO_3)_2 \) has 1 Ni, 2 Cl, 6 O.
• Products: \( NiCl_2 \) (1 Ni, 2 Cl), \( O_2 \) (2 O).
• Ni and Cl: balanced (1 Ni, 2 Cl).
• Balance O: 6 O in reactants. \( O_2 \) needs 3 (6/2). So coefficients: 1 \( Ni(ClO_3)_2 \) → 1 \( NiCl_2 \) + 3 \( O_2 \).
• Reactants (Ni: 1, Cl: 2, O: 6); Products (Ni: 1, Cl: 2, O: 6).

Step 7: Balance Equation 13

• Reactants: HCl has 1 H, 1 Cl.
• Products: \( H_2 \) (2 H), \( Cl_2 \) (2 Cl).
• Balance H: Put 2 in front of HCl. Now HCl: 2 H, 2 Cl.
• Products: \( H_2 \) (1) and \( Cl_2 \) (1). So coefficients: 2 HCl → 1 \( H_2 \) + 1 \( Cl_2 \).
• Reactants (H: 2, Cl: 2); Products (H: 2, Cl: 2).

Answer:

1. 2 NaOH → 1 \( Na_2O \) + 1 \( H_2O \)

Reactants: Na=2, O=2, H=2; Products: Na=2, O=2, H=2

1. 2 \( Al_2O_3 \) → 4 Al + 3 \( O_2 \)

Reactants: Al=4, O=6; Products: Al=4, O=6

1. 1 \( K_2CO_3 \) → 1 \( K_2O \) + 1 \( CO_2 \)

Reactants: K=2, C=1, O=3; Products: K=2, C=1, O=3

1. 1 \( Zn(OH)_2 \) → 1 ZnO + 1 \( H_2O \)

Reactants: Zn=1, O=2, H=2; Products: Zn=1, O=2, H=2

1. 2 \( Ag_2O \) → 4 Ag + 1 \( O_2 \)

Reactants: Ag=4, O=2; Products: Ag=4, O=2

1. 1 \( Ni(ClO_3)_2 \) → 1 \( NiCl_2 \) + 3 \( O_2 \)

Reactants: Ni=1, Cl=2, O=6; Products: Ni=1, Cl=2, O=6

1. 2 HCl → 1 \( H_2 \) + 1 \( Cl_2 \)

Reactants: H=2, Cl=2; Products: H=2, Cl=2