Question

practice problems
identify the reactants, the products and the coefficients of these equations:

1. zn + 2 hcl ---> zncl₂ + h₂
2. 2kclo₃ ---> 2kcl + 3o₂
3. s₈ + 24f₂ ---> 8sf₆
4. 4fe + 3o₂ ---> 2fe₂o₃
5. 2c₂h₆ + 7o₂ ---> 4co₂ + 6h₂o

Explanation:

Step1: Reactants and Products Identification

In a chemical equation, the substances on the left - hand side of the arrow ($
ightarrow$) are reactants, and the substances on the right - hand side are products.

Step2: Coefficient Identification

Coefficients are the numerical values in front of the chemical formulas.

For equation 1: $Zn + 2HCl

ightarrow ZnCl_{2}+H_{2}$

• Reactants: $Zn$ (zinc) and $HCl$ (hydrochloric acid)
• Products: $ZnCl_{2}$ (zinc chloride) and $H_{2}$ (hydrogen gas)
• Coefficients: $1$ (for $Zn$), $2$ (for $HCl$), $1$ (for $ZnCl_{2}$), $1$ (for $H_{2}$)

For equation 2: $2KClO_{3}

ightarrow 2KCl + 3O_{2}$

• Reactants: $KClO_{3}$ (potassium chlorate)
• Products: $KCl$ (potassium chloride) and $O_{2}$ (oxygen gas)
• Coefficients: $2$ (for $KClO_{3}$), $2$ (for $KCl$), $3$ (for $O_{2}$)

For equation 3: $S_{8}+24F_{2}

ightarrow 8SF_{6}$

• Reactants: $S_{8}$ (sulfur) and $F_{2}$ (fluorine gas)
• Products: $SF_{6}$ (sulfur hexafluoride)
• Coefficients: $1$ (for $S_{8}$), $24$ (for $F_{2}$), $8$ (for $SF_{6}$)

For equation 4: $4Fe + 3O_{2}

ightarrow 2Fe_{2}O_{3}$

• Reactants: $Fe$ (iron) and $O_{2}$ (oxygen gas)
• Products: $Fe_{2}O_{3}$ (iron(III) oxide)
• Coefficients: $4$ (for $Fe$), $3$ (for $O_{2}$), $2$ (for $Fe_{2}O_{3}$)

For equation 5: $2C_{2}H_{6}+7O_{2}

ightarrow 4CO_{2}+6H_{2}O$

• Reactants: $C_{2}H_{6}$ (ethane) and $O_{2}$ (oxygen gas)
• Products: $CO_{2}$ (carbon dioxide) and $H_{2}O$ (water)
• Coefficients: $2$ (for $C_{2}H_{6}$), $7$ (for $O_{2}$), $4$ (for $CO_{2}$), $6$ (for $H_{2}O$)

Answer:

1. Reactants: $Zn$, $HCl$; Products: $ZnCl_{2}$, $H_{2}$; Coefficients: $1$, $2$, $1$, $1$
2. Reactants: $KClO_{3}$; Products: $KCl$, $O_{2}$; Coefficients: $2$, $2$, $3$
3. Reactants: $S_{8}$, $F_{2}$; Products: $SF_{6}$; Coefficients: $1$, $24$, $8$
4. Reactants: $Fe$, $O_{2}$; Products: $Fe_{2}O_{3}$; Coefficients: $4$, $3$, $2$
5. Reactants: $C_{2}H_{6}$, $O_{2}$; Products: $CO_{2}$, $H_{2}O$; Coefficients: $2$, $7$, $4$, $6$