Question

type the number of the coefficient needed to balance the number of oxygen atoms in the chemical equation shown.
$\ce{c_{3}h_{8} + ?o_{2} -> 3co_{2} + 4h_{2}o}$
5
which list of coefficients will balance the chemical equation shown?
$\ce{\\_hbr + \\_ca(oh)_{2} -> \\_cabr_{2} + \\_h_{2}o}$
$\bigcirc$ 2, 1, 2, 1
$\bigcirc$ 1, 2, 1, 2
$\bigcirc$ 1, 2, 2, 1
$\bigcirc$ 2, 1, 1, 2
how many oxygen atoms will be on the reactant side of the

Explanation:

Step1: Count product oxygen atoms

Count O in $\text{CO}_2$ and $\text{H}_2\text{O}$:
$(3 \times 2) + (4 \times 1) = 6 + 4 = 10$

Step2: Solve for $\text{O}_2$ coefficient

Let coefficient be $x$. $2x = 10$, so $x = \frac{10}{2} = 5$

Step3: Balance HBr for Br atoms

Match Br in $\text{CaBr}_2$: coefficient = 2

Step4: Balance $\text{H}_2\text{O}$ for H atoms

H from 2 HBr: $\frac{2}{1} = 2$

Step5: Verify all atoms balanced

Check Ca, O, H, Br counts on both sides.

Answer:

1. 5
2. 2, 1, 1, 2