The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is:
[Given that H = 1, O = 16]

Options

A. 1:2
B. 1: 0.01
C. 1:1
D. 0:01 : 1

Explanation

To find the ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen, we can follow these steps:

### Step 1: Calculate the number of moles of hydrogen (H₂)
- Given mass of hydrogen = 2 g
- Molar mass of hydrogen (H₂) = 2 × atomic mass of H = 2 × 1 = 2 g/mol

Using the formula for moles:
\[ \text{Number of moles of H₂} = \frac{\text{Given mass}}{\text{Molar mass}} = \frac{2 \text{ g}}{2 \text{ g/mol}} = 1 \text{ mole} \]

### Step 2: Calculate the number of molecules of hydrogen
- We know that 1 mole of any substance contains \(6.022 \times 10^{23}\) molecules (Avogadro's number).
\[ \text{Number of molecules of H₂} = 1 \text{ mole} \times 6.022 \times 10^{23} \text{ molecules/mole} = 6.022 \times 10^{23} \text{ molecules} \]

### Step 3: Calculate the number of moles of oxygen (O₂)
- Given mass of oxygen = 32 g
- Molar mass of oxygen (O₂) = 2 × atomic mass of O = 2 × 16 = 32 g/mol

Using the formula for moles:
\[ \text{Number of moles of O₂} = \frac{\text{Given mass}}{\text{Molar mass}} = \frac{32 \text{ g}}{32 \text{ g/mol}} = 1 \text{ mole} \]

### Step 4: Calculate the number of molecules of oxygen
- Similarly, for oxygen:
\[ \text{Number of molecules of O₂} = 1 \text{ mole} \times 6.022 \times 10^{23} \text{ molecules/mole} = 6.022 \times 10^{23} \text{ molecules} \]

### Step 5: Calculate the ratio of the number of molecules of hydrogen to that of oxygen
\[ \text{Ratio} = \frac{\text{Number of molecules of H₂}}{\text{Number of molecules of O₂}} = \frac{6.022 \times 10^{23}}{6.022 \times 10^{23}} = 1:1 \]

### Final Answer
The ratio between the number of molecules in 2 g of hydrogen and 32 g of oxygen is **1:1**.

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