Question

activity: practice balancing chemical equations
balance the equations and name the types of reactions.

1. __n₂ + h₂ —→ __nh₃ \t\t\t\ttype of reaction
2. __na + h₂o —→ naoh + __h₂ \t\t\t\t
3. __kclo₃ —→ kcl + __o₂ \t\t\t\t
4. __nacl + f₂ —→ naf + __cl₂ \t\t\t\t
5. __h₂ + o₂ —→ __h₂o \t\t\t\t
6. __pb(oh)₂ + hcl —→ h₂o + __pbcl₂ \t\t\t\t
7. __albr₃ + k₂so₄ —→ kbr + __al₂(so₄)₃ \t\t\t\t
8. __c₃h₈ + o₂ —→ co₂ + __h₂o \t\t\t\t
9. __fecl₃ + naoh —→ fe(oh)₃ + __nacl \t\t\t\t

write the correct answers.

1. solid sodium chloride and fluorine gas react to form solid sodium fluoride and chlorine gas.

a. write a formula equation. (include the physical state of each reactant and product.)

b. now balance the equation and write a complete chemical equation.

1. aqueous potassium iodide and aqueous lead (ii) nitrate react to form aqueous potassium nitrate and solid lead (ii) iodide.

a. write a formula equation. (include the physical state of each reactant and product.)

b. now balance the equation and write a complete chemical equation.

Explanation:

Step1: Balance equation 1, classify reaction

$1\text{N}_2 + 3\text{H}_2 \longrightarrow 2\text{NH}_3$
Reaction type: Synthesis (Combination)

Step2: Balance equation 2, classify reaction

$2\text{Na} + 2\text{H}_2\text{O} \longrightarrow 2\text{NaOH} + 1\text{H}_2$
Reaction type: Single Displacement

Step3: Balance equation 3, classify reaction

$2\text{KClO}_3 \longrightarrow 2\text{KCl} + 3\text{O}_2$
Reaction type: Decomposition

Step4: Balance equation 4, classify reaction

$2\text{NaCl} + 1\text{F}_2 \longrightarrow 2\text{NaF} + 1\text{Cl}_2$
Reaction type: Single Displacement

Step5: Balance equation 5, classify reaction

$2\text{H}_2 + 1\text{O}_2 \longrightarrow 2\text{H}_2\text{O}$
Reaction type: Synthesis (Combination)

Step6: Balance equation 6, classify reaction

$1\text{Pb(OH)}_2 + 2\text{HCl} \longrightarrow 2\text{H}_2\text{O} + 1\text{PbCl}_2$
Reaction type: Double Displacement (Neutralization)

Step7: Balance equation 7, classify reaction

$2\text{AlBr}_3 + 3\text{K}_2\text{SO}_4 \longrightarrow 6\text{KBr} + 1\text{Al}_2(\text{SO}_4)_3$
Reaction type: Double Displacement

Step8: Balance equation 8, classify reaction

$1\text{C}_3\text{H}_8 + 5\text{O}_2 \longrightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$
Reaction type: Combustion

Step9: Balance equation 9, classify reaction

$1\text{FeCl}_3 + 3\text{NaOH} \longrightarrow 1\text{Fe(OH)}_3 + 3\text{NaCl}$
Reaction type: Double Displacement

Step10a: Write unbalanced state equation

$\text{NaCl}(s) + \text{F}_2(g) \longrightarrow \text{NaF}(s) + \text{Cl}_2(g)$

Step10b: Balance state equation

$2\text{NaCl}(s) + \text{F}_2(g) \longrightarrow 2\text{NaF}(s) + \text{Cl}_2(g)$

Step11a: Write unbalanced state equation

$\text{KI}(aq) + \text{Pb(NO}_3\text{)}_2(aq) \longrightarrow \text{KNO}_3(aq) + \text{PbI}_2(s)$

Step11b: Balance state equation

$2\text{KI}(aq) + \text{Pb(NO}_3\text{)}_2(aq) \longrightarrow 2\text{KNO}_3(aq) + \text{PbI}_2(s)$

Answer:

1. Balanced equation: $\boldsymbol{1\text{N}_2 + 3\text{H}_2 \longrightarrow 2\text{NH}_3}$; Reaction type: Synthesis (Combination)
2. Balanced equation: $\boldsymbol{2\text{Na} + 2\text{H}_2\text{O} \longrightarrow 2\text{NaOH} + 1\text{H}_2}$; Reaction type: Single Displacement
3. Balanced equation: $\boldsymbol{2\text{KClO}_3 \longrightarrow 2\text{KCl} + 3\text{O}_2}$; Reaction type: Decomposition
4. Balanced equation: $\boldsymbol{2\text{NaCl} + 1\text{F}_2 \longrightarrow 2\text{NaF} + 1\text{Cl}_2}$; Reaction type: Single Displacement
5. Balanced equation: $\boldsymbol{2\text{H}_2 + 1\text{O}_2 \longrightarrow 2\text{H}_2\text{O}}$; Reaction type: Synthesis (Combination)
6. Balanced equation: $\boldsymbol{1\text{Pb(OH)}_2 + 2\text{HCl} \longrightarrow 2\text{H}_2\text{O} + 1\text{PbCl}_2}$; Reaction type: Double Displacement (Neutralization)
7. Balanced equation: $\boldsymbol{2\text{AlBr}_3 + 3\text{K}_2\text{SO}_4 \longrightarrow 6\text{KBr} + 1\text{Al}_2(\text{SO}_4)_3}$; Reaction type: Double Displacement
8. Balanced equation: $\boldsymbol{1\text{C}_3\text{H}_8 + 5\text{O}_2 \longrightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}}$; Reaction type: Combustion
9. Balanced equation: $\boldsymbol{1\text{FeCl}_3 + 3\text{NaOH} \longrightarrow 1\text{Fe(OH)}_3 + 3\text{NaCl}}$; Reaction type: Double Displacement

10a) Unbalanced formula equation: $\boldsymbol{\text{NaCl}(s) + \text{F}_2(g) \longrightarrow \text{NaF}(s) + \text{Cl}_2(g)}$
10b) Balanced complete equation: $\boldsymbol{2\text{NaCl}(s) + \text{F}_2(g) \longrightarrow 2\text{NaF}(s) + \text{Cl}_2(g)}$
11a) Unbalanced formula equation: $\boldsymbol{\text{KI}(aq) + \text{Pb(NO}_3\text{)}_2(aq) \longrightarrow \text{KNO}_3(aq) + \text{PbI}_2(s)}$
11b) Balanced complete equation: $\boldsymbol{2\text{KI}(aq) + \text{Pb(NO}_3\text{)}_2(aq) \longrightarrow 2\text{KNO}_3(aq) + \text{PbI}_2(s)}$