A mixutre of Cu, Fe, and Al was reacted with 13.33 g of NaOH. During chlorination with the same amount of meta mixture entered into reaction with 12.5 L of chlorine measured at STP, while for treating the same amound of the metal mixture at STP, while for treating the same amound of the metal mix mixutre
`343.64` " mL of " HCl, havig a density of `.1g mL^(-1)` and containing `10%` by mass of HCl were required. Determine the mass percentage of the metals in the mixture.

Explanation

To determine the mass percentage of Cu, Fe, and Al in the mixture, we will follow these steps:

### Step 1: Calculate Moles of NaOH
Given that 13.33 g of NaOH was used, we can calculate the moles of NaOH using its molar mass.

\[ \text{Molar mass of NaOH} = 23 + 16 + 1 = 40 \, \text{g/mol} \]
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