Question

when the equation below is balanced using the smallest whole number coefficients, what is the sum of all the coefficients?
c₂h₄(g) + o₂(g) → co₂(g) + h₂o(l)
a 4
b 8
c 16
d 12
check it

Explanation:

Step1: Balance the carbon atoms

The chemical formula of ethylene is \(C_2H_4\). In the product \(CO_2\), for carbon balance, if we have \(C_2H_4\), then the coefficient of \(CO_2\) should be \(2\) (because there are \(2\) carbon atoms in \(C_2H_4\)). So the equation becomes \(C_2H_4+O_2
ightarrow2CO_2 + H_2O\).

Step2: Balance the hydrogen atoms

In \(C_2H_4\), there are \(4\) hydrogen atoms. In \(H_2O\), to balance the hydrogen atoms, since each \(H_2O\) molecule has \(2\) hydrogen atoms, the coefficient of \(H_2O\) should be \(2\). Now the equation is \(C_2H_4+O_2
ightarrow2CO_2 + 2H_2O\).

Step3: Balance the oxygen atoms

On the right - hand side, in \(2CO_2\) there are \(2\times2 = 4\) oxygen atoms and in \(2H_2O\) there are \(2\times1=2\) oxygen atoms. So in total, there are \(4 + 2=6\) oxygen atoms on the right - hand side. Since each \(O_2\) molecule has \(2\) oxygen atoms, the coefficient of \(O_2\) should be \(3\). The balanced equation is \(C_2H_4+3O_2 = 2CO_2+2H_2O\).

Step4: Calculate the sum of coefficients

The sum of coefficients is \(1 + 3+2 + 2\).

$$1+3+2 + 2=8$$

Answer:

b 8