To balance the equation \( \text{CH}_4 + ____ \text{Cl}_2 \rightarrow \text{CCl}_4 + ____ \text{HCl} \), let's analyze the number of each type of atom on both sides of the equation.
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On the left side, we have:
- Carbon (C): 1 (from CH4)
- Hydrogen (H): 4 (from CH4)
- Chlorine (Cl): We will determine this.
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On the right side, we have:
- Carbon (C): 1 (from CCl4)
- Hydrogen (H): 1 (from HCl)
- Chlorine (Cl): 4 (from CCl4)
Now, we can balance the chlorine and hydrogen:
To balance the chlorine (on the right side we have 4 Cl from CCl4):
- We need 2 Cl2 molecules on the left to get 4 Cl atoms.
- This gives us: \( \text{CH}_4 + 2 \text{Cl}_2 \rightarrow \text{CCl}_4 + ____ \text{HCl} \).
With this, we have:
- Left side Cl: 4
- Right side Cl: 4
For hydrogen:
- On the left, there are 4 H from CH4.
- On the right, we need 4 HCl molecules to balance the H on the right, which gives us 4 H.
Thus, the balanced equation is:
\[ \text{CH}_4 + 2 \text{Cl}_2 \rightarrow \text{CCl}_4 + 4 \text{HCl} \]
So the numbers that balance this equation are:
- 2 for Cl2
- 4 for HCl
Therefore, the answer is 2, 4.