Positive and negative charge in 18 cc of water is

Options

A. `q=(+-)9.63X 10^5 C`
B. `q=(+-)1.63X 10^5 `C
C. `q=(+-)9.63X 10^(-5)C`
D. `q=(+-)2.63X 10^(-5) C`

Answer

To find the positive and negative charge in 18 cc (or 18 ml) of water, we can follow these steps:

### Step 1: Determine the mass of water
Given that the density of water is 1 g/ml, we can calculate the mass of 18 ml of water.

\[ \text{Mass of water} = \text{Volume} \times \text{Density} = 18 \, \text{ml} \times 1 \, \text{g/ml} = 18 \, \text{g} \]

### Step 2: Calculate the number of moles of water
The molecular weight of water (H₂O) is 18 g/mol. We can use this to find the number of moles of water.

\[ \text{Number of moles of water} (n) = \frac{\text{Mass}}{\text{Molecular weight}} = \frac{18 \, \text{g}}{18 \, \text{g/mol}} = 1 \, \text{mol} \]

### Step 3: Determine the number of electrons in water
Each molecule of water (H₂O) contains 10 electrons (2 from hydrogen and 8 from oxygen). Therefore, the total number of electrons in 1 mole of water is:

\[ \text{Number of electrons} = \text{Number of moles of water} \times \text{Electrons per molecule} = 1 \, \text{mol} \times 10 = 10 \, \text{mol of electrons} \]

### Step 4: Calculate the total number of electrons
Using Avogadro's number (\(N_A = 6.02 \times 10^{23}\) electrons/mol), we can find the total number of electrons:

\[ \text{Total number of electrons} = 10 \, \text{mol} \times 6.02 \times 10^{23} \, \text{electrons/mol} = 6.02 \times 10^{24} \, \text{electrons} \]

### Step 5: Calculate the total charge of the electrons
The charge of one electron is approximately \(1.6 \times 10^{-19}\) coulombs. Therefore, the total charge (Q) can be calculated as follows:

\[ Q = \text{Total number of electrons} \times \text{Charge of one electron} = 6.02 \times 10^{24} \times 1.6 \times 10^{-19} \, \text{C} \]

Calculating this gives:

\[ Q \approx 9.632 \times 10^{5} \, \text{C} \]

### Step 6: Determine the positive and negative charges
Since water is a neutral molecule, the positive charge and negative charge will be equal in magnitude but opposite in sign. Thus:

- Positive charge in 18 cc of water: \(+9.632 \times 10^{5} \, \text{C}\)
- Negative charge in 18 cc of water: \(-9.632 \times 10^{5} \, \text{C}\)

### Final Answer
Positive charge = \(+9.632 \times 10^{5} \, \text{C}\)
Negative charge = \(-9.632 \times 10^{5} \, \text{C}\)

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