The number of water molecules is maximum in

Options

A. 18 molecules water
B. 1.8 g of water
C. 18 g of water
D. 18 moles of water

Explanation

To solve the question regarding which option has the maximum number of water molecules, we will analyze each option step by step.

### Step 1: Analyze the options
The options given are:
1. 18 molecules of water
2. 1.8 grams of water
3. 18 grams of water
4. 18 moles of water

### Step 2: Calculate the number of water molecules for each option

#### Option 1: 18 molecules of water
- This option directly states that there are 18 molecules of water.
- **Number of molecules = 18**

#### Option 2: 1.8 grams of water
- First, we need to calculate the number of moles of water in 1.8 grams.
- The molecular mass of water (H₂O) is 18 g/mol.
- Number of moles (n) = mass (g) / molar mass (g/mol) = 1.8 g / 18 g/mol = 0.1 moles
- Now, we calculate the number of molecules using Avogadro's number (6.022 x 10²³ molecules/mol):
- Number of molecules = n × Avogadro's number = 0.1 moles × 6.022 x 10²³ molecules/mol = 6.022 x 10²² molecules

#### Option 3: 18 grams of water
- Calculate the number of moles of water in 18 grams.
- Number of moles (n) = mass (g) / molar mass (g/mol) = 18 g / 18 g/mol = 1 mole
- Number of molecules = n × Avogadro's number = 1 mole × 6.022 x 10²³ molecules/mol = 6.022 x 10²³ molecules

#### Option 4: 18 moles of water
- Here, we are given 18 moles directly.
- Number of molecules = n × Avogadro's number = 18 moles × 6.022 x 10²³ molecules/mol = 1.084 x 10²⁵ molecules

### Step 3: Compare the number of molecules from each option
- Option 1: 18 molecules
- Option 2: 6.022 x 10²² molecules
- Option 3: 6.022 x 10²³ molecules
- Option 4: 1.084 x 10²⁵ molecules

### Conclusion
The maximum number of water molecules is in **Option 4: 18 moles of water**.

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