Two oxides of copper contain respectively 88.8% and 79.91 % of copper. Calculate equivalent masses of copper in each of the oxide.

Answer

To calculate the equivalent masses of copper in the two oxides, we will follow these steps:

### Step 1: Understanding the Composition of the Oxides
We have two oxides of copper with the following percentages of copper:
- Oxide 1: 88.8% copper
- Oxide 2: 79.91% copper

### Step 2: Setting Up the Mass of the Oxides
Let’s assume we have 100 grams of each oxide for simplicity. This means:
- In Oxide 1, the mass of copper = 88.8 grams
- In Oxide 2, the mass of copper = 79.91 grams

### Step 3: Finding the Mass of Oxygen in Each Oxide
To find the mass of oxygen, we subtract the mass of copper from the total mass of the oxide (100 grams):
- For Oxide 1:
\[ \text{Mass of Oxygen} = 100 \text{ g} - 88.8 \text{ g} = 11.2 \text{ g} \]
- For Oxide 2:
\[ \text{Mass of Oxygen} = 100 \text{ g} - 79.91 \text{ g} = 20.09 \text{ g} \]

### Step 4: Calculating the Equivalent Mass of Copper
The equivalent mass of a substance is defined as the mass of the substance that combines with or displaces 1 mole of hydrogen (or 8 grams of oxygen). The formula for calculating the equivalent mass of copper in each oxide is:
\[ \text{Equivalent mass of Copper} = \frac{\text{Mass of Copper}}{\text{Mass of Oxygen} / 8} \]

#### For Oxide 1:
\[ \text{Equivalent mass of Copper} = \frac{88.8 \text{ g}}{11.2 \text{ g} / 8} \]
Calculating the denominator:
\[ \frac{11.2}{8} = 1.4 \]
Now substituting back:
\[ \text{Equivalent mass of Copper} = \frac{88.8}{1.4} = 63.43 \text{ g} \]

#### For Oxide 2:
\[ \text{Equivalent mass of Copper} = \frac{79.91 \text{ g}}{20.09 \text{ g} / 8} \]
Calculating the denominator:
\[ \frac{20.09}{8} = 2.51125 \]
Now substituting back:
\[ \text{Equivalent mass of Copper} = \frac{79.91}{2.51125} \approx 31.8 \text{ g} \]

### Final Results:
- Equivalent mass of copper in Oxide 1 = 63.43 g
- Equivalent mass of copper in Oxide 2 = 31.8 g

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