worksheet #6: combustion reactions we will focus on the combustion of hydrocarbons. hydrocarbons react with…

Explanation:

Step1: Balance methane combustion

The un - balanced equation is $CH_4+O_2\rightarrow CO_2 + H_2O$. Balance hydrogen first. Since there are 4 H in $CH_4$, we need 2 moles of $H_2O$. Then balance oxygen. The balanced equation is $CH_4 + 2O_2\rightarrow CO_2+2H_2O$.

Step2: Balance ethane combustion

The un - balanced equation is $C_2H_6+O_2\rightarrow CO_2 + H_2O$. Balance carbon first. 2 moles of $CO_2$ are needed for 2 C in $C_2H_6$. Then balance hydrogen. 3 moles of $H_2O$ are needed for 6 H in $C_2H_6$. Finally, balance oxygen. The balanced equation is $2C_2H_6+7O_2\rightarrow 4CO_2 + 6H_2O$.

Step3: Balance propane combustion

The un - balanced equation is $C_3H_8+O_2\rightarrow CO_2 + H_2O$. For 3 C in $C_3H_8$, we need 3 moles of $CO_2$. For 8 H in $C_3H_8$, we need 4 moles of $H_2O$. Then balance oxygen. The balanced equation is $C_3H_8+5O_2\rightarrow 3CO_2+4H_2O$.

Step4: Balance butane combustion

The un - balanced equation is $C_4H_{10}+O_2\rightarrow CO_2 + H_2O$. For 4 C in $C_4H_{10}$, we need 4 moles of $CO_2$. For 10 H in $C_4H_{10}$, we need 5 moles of $H_2O$. Then balance oxygen. The balanced equation is $2C_4H_{10}+13O_2\rightarrow 8CO_2 + 10H_2O$.

Step5: Balance pentane combustion

The un - balanced equation is $C_5H_{12}+O_2\rightarrow CO_2 + H_2O$. For 5 C in $C_5H_{12}$, we need 5 moles of $CO_2$. For 12 H in $C_5H_{12}$, we need 6 moles of $H_2O$. Then balance oxygen. The balanced equation is $C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O$.

Step6: Balance hexane combustion

The un - balanced equation is $C_6H_{14}+O_2\rightarrow CO_2 + H_2O$. For 6 C in $C_6H_{14}$, we need 6 moles of $CO_2$. For 14 H in $C_6H_{14}$, we need 7 moles of $H_2O$. Then balance oxygen. The balanced equation is $2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O$.

Step7: Balance ethene combustion

The un - balanced equation is $C_2H_4+O_2\rightarrow CO_2 + H_2O$. For 2 C in $C_2H_4$, we need 2 moles of $CO_2$. For 4 H in $C_2H_4$, we need 2 moles of $H_2O$. Then balance oxygen. The balanced equation is $C_2H_4+3O_2\rightarrow 2CO_2+2H_2O$.

Step8: Balance ethyne combustion

The un - balanced equation is $C_2H_2+O_2\rightarrow CO_2 + H_2O$. For 2 C in $C_2H_2$, we need 2 moles of $CO_2$. For 2 H in $C_2H_2$, we need 1 mole of $H_2O$. Then balance oxygen. The balanced equation is $2C_2H_2+5O_2\rightarrow 4CO_2+2H_2O$.

Step9: Balance benzene combustion

The un - balanced equation is $C_6H_6+O_2\rightarrow CO_2 + H_2O$. For 6 C in $C_6H_6$, we need 6 moles of $CO_2$. For 6 H in $C_6H_6$, we need 3 moles of $H_2O$. Then balance oxygen. The balanced equation is $2C_6H_6+15O_2\rightarrow 12CO_2+6H_2O$.

Answer:

1. $CH_4 + 2O_2\rightarrow CO_2+2H_2O$
2. $2C_2H_6+7O_2\rightarrow 4CO_2 + 6H_2O$
3. $C_3H_8+5O_2\rightarrow 3CO_2+4H_2O$
4. $2C_4H_{10}+13O_2\rightarrow 8CO_2 + 10H_2O$
5. $C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O$
6. $2C_6H_{14}+19O_2\rightarrow 12CO_2+14H_2O$
7. $C_2H_4+3O_2\rightarrow 2CO_2+2H_2O$
8. $2C_2H_2+5O_2\rightarrow 4CO_2+2H_2O$
9. $2C_6H_6+15O_2\rightarrow 12CO_2+6H_2O$