The weight of water in 1 litre of 2 M NaCl solution of density `1.117 g//mL` is

Options

A. 1117g
B. 1000g
C. 117g
D. 883g

Answer

To find the weight of water in 1 liter of a 2 M NaCl solution with a density of 1.117 g/mL, we can follow these steps:

### Step 1: Calculate the total mass of the solution
Since the density of the solution is given as 1.117 g/mL, we can calculate the total mass of 1 liter (1000 mL) of the solution.

\[ \text{Mass of solution} = \text{Density} \times \text{Volume} = 1.117 \, \text{g/mL} \times 1000 \, \text{mL} = 1117 \, \text{g} \]

### Step 2: Calculate the number of moles of NaCl
The molarity (M) of the solution is given as 2 M, which means there are 2 moles of NaCl in 1 liter of solution.

\[ \text{Number of moles of NaCl} = 2 \, \text{moles} \]

### Step 3: Calculate the mass of NaCl
To find the mass of NaCl, we need to know its molar mass. The molar mass of NaCl (sodium chloride) is approximately:

\[ \text{Molar mass of NaCl} = \text{Molar mass of Na} + \text{Molar mass of Cl} = 23 \, \text{g/mol} + 35.5 \, \text{g/mol} = 58.5 \, \text{g/mol} \]

Now, we can calculate the mass of 2 moles of NaCl:

\[ \text{Mass of NaCl} = \text{Number of moles} \times \text{Molar mass} = 2 \, \text{moles} \times 58.5 \, \text{g/mol} = 117 \, \text{g} \]

### Step 4: Calculate the mass of water in the solution
Now that we have the total mass of the solution and the mass of NaCl, we can find the mass of water by subtracting the mass of NaCl from the total mass of the solution.

\[ \text{Mass of water} = \text{Mass of solution} - \text{Mass of NaCl} = 1117 \, \text{g} - 117 \, \text{g} = 1000 \, \text{g} \]

### Final Answer
The weight of water in 1 liter of 2 M NaCl solution is **1000 g**.

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