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 of water, we can follow these steps:

### Step 1: Determine the mass of water
Given that the density of water is 1 gram per cubic centimeter (g/cm³), we can calculate the mass of 18 cc of water.

\[ \text{Mass} = \text{Density} \times \text{Volume} = 1 \, \text{g/cm}^3 \times 18 \, \text{cm}^3 = 18 \, \text{grams} \]

### Step 2: Calculate the number of water molecules
The molecular formula of water is H₂O, which means each molecule contains 2 hydrogen atoms and 1 oxygen atom. The molar mass of water is approximately 18 g/mol.

Using Avogadro's number (approximately \(6.02 \times 10^{23}\) molecules/mol), we can find the number of molecules in 18 grams of water:

\[ \text{Number of moles} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{18 \, \text{g}}{18 \, \text{g/mol}} = 1 \, \text{mol} \]

\[ \text{Number of molecules} = 1 \, \text{mol} \times 6.02 \times 10^{23} \, \text{molecules/mol} = 6.02 \times 10^{23} \, \text{molecules} \]

### Step 3: Calculate the number of electrons
Each water molecule (H₂O) has 10 electrons (2 from hydrogen and 8 from oxygen). Therefore, the total number of electrons in 18 cc of water is:

\[ \text{Total electrons} = 10 \, \text{electrons/molecule} \times 6.02 \times 10^{23} \, \text{molecules} = 6.02 \times 10^{24} \, \text{electrons} \]

### Step 4: Calculate the total charge
The charge of a single electron is approximately \(-1.6 \times 10^{-19}\) coulombs. Thus, the total negative charge due to electrons is:

\[ \text{Total negative charge} = \text{Number of electrons} \times \text{Charge of one electron} \]

\[ = 6.02 \times 10^{24} \times (-1.6 \times 10^{-19}) = -9.632 \times 10^{5} \, \text{coulombs} \]

Since protons have the same magnitude of charge but are positive, the total positive charge is:

\[ \text{Total positive charge} = 9.632 \times 10^{5} \, \text{coulombs} \]

### Final Answer
The positive and negative charge in 18 cc of water is approximately:

\[ \pm 9.63 \times 10^{5} \, \text{coulombs} \]

### Conclusion
Thus, the correct option is:
**q = ± 9.63 × 10⁵ coulombs.**

---