18. What is the stoichiometric coefficient for water when the following equation showing the combustion of propanol is balanced with the smallest whole number coefficients? C_(3)H_(7)OH+O_(2)arrow CO_(2)+H_(2)O A) 3 B) 8 C) 13 D) 4 E) 1

To balance the equation, we need to ensure that the number of atoms of each element is the same on both sides of the equation.<br /><br />Let's start by balancing the carbon atoms. There are 3 carbon atoms in propanol and 1 carbon atom in carbon dioxide. To balance the carbon atoms, we need to have 3 carbon dioxide molecules on the right side of the equation. The equation now looks like this:<br /><br />$C_{3}H_{7}OH+O_{2}\rightarrow 3CO_{2}+H_{2}O$<br /><br />Next, let's balance the hydrogen atoms. There are 8 hydrogen atoms in propanol and 2 hydrogen atoms in water. To balance the hydrogen atoms, we need to have 4 water molecules on the right side of the equation. The equation now looks like this:<br /><br />$C_{3}H_{7}OH+O_{2}\rightarrow 3CO_{2}+4H_{2}O$<br /><br />Finally, let's balance the oxygen atoms. There are 1 oxygen atom in propanol, 2 oxygen atoms in each carbon dioxide molecule, and 1 oxygen atom in each water molecule. To balance the oxygen atoms, we need to have 5 oxygen molecules on the left side of the equation. The equation now looks like this:<br /><br />$C_{3}H_{7}OH+5O_{2}\rightarrow 3CO_{2}+4H_{2}O$<br /><br />The stoichiometric coefficient for water in the balanced equation is 4. Therefore, the correct answer is D) 4.