A solution of NaOH is contained within a Class A 1-L volumetric flask filled to the calibration mark. The content label reads 24 g of NaOH. Determine the molarity. Step 1: What units are ultimately needed? Answer: Moles per liter (mol/L). Step 2: The units that exist are grams and L. NaOH may be expressed as moles and grams. The gmw of NaOH is calculated to equal 40 g/mol. Rearrange the equation so that grams can be canceled and the remaining units reflect those needed in the answer, which are mole/L. Step 3: The equation becomes
24g NaOH 1 mol L 40g NaOH mol 0.6-L (Eq. 1-25)
By canceling out like units and performing the appropriate calculations, the final answer of 0.6 M or 0.6 mol/L is derived.
The Correct Answer and Explanation is :
To calculate the molarity of the NaOH solution, we begin by following a systematic approach. Here’s a detailed breakdown of the steps:
Step 1: Determine the Units Needed
The desired unit for molarity is moles per liter (mol/L), which indicates how many moles of solute (NaOH) are present in one liter of solution.
Step 2: Units Already Given
The problem provides 24 grams of NaOH and the volume of solution, which is 1 liter. To get the molarity (mol/L), we need to convert grams of NaOH to moles.
Step 3: Find the Molar Mass (GMW) of NaOH
The molar mass (or GMW) of NaOH is the sum of the atomic masses of sodium (Na), oxygen (O), and hydrogen (H):
- Na: 23 g/mol
- O: 16 g/mol
- H: 1 g/mol
Therefore, the molar mass of NaOH is (23 + 16 + 1 = 40 \, \text{g/mol}).
Step 4: Set Up the Equation
We want to convert grams to moles. Since the molar mass of NaOH is 40 g/mol, we can use the following equation to find the number of moles:
[
\text{moles of NaOH} = \frac{\text{grams of NaOH}}{\text{molar mass of NaOH}} = \frac{24 \, \text{g}}{40 \, \text{g/mol}} = 0.6 \, \text{mol}.
]
Now that we know we have 0.6 moles of NaOH in the solution, we can calculate the molarity.
Step 5: Calculate the Molarity
Molarity (M) is defined as the number of moles of solute divided by the volume of the solution in liters:
[
\text{Molarity (M)} = \frac{\text{moles of NaOH}}{\text{volume of solution in liters}} = \frac{0.6 \, \text{mol}}{1 \, \text{L}} = 0.6 \, \text{mol/L}.
]
Thus, the molarity of the NaOH solution is 0.6 M.
Final Answer:
The molarity of the NaOH solution is 0.6 M or 0.6 mol/L.
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Here is the step-by-step diagram showing how to calculate the molarity of the NaOH solution. It breaks down the process of converting grams of NaOH to moles, and then calculating the molarity based on the given data. Let me know if you need any further explanations or adjustments!
