Title: Understanding the Concentration of NaCl Solutions
1. How many grams of NaCl are in a 100 ml solution that is 2.5 M?
The correct answer is option C) 58.0 grams.
2. What is the % w/v of a NaCl solution made by placing 100 grams into making 750 ml of solution?
The correct answer is option B) 13.3%.
Answer:
To calculate the number of grams of NaCl in a 100 ml solution, we need to use the formula:
grams = moles × molar mass
First, calculate the number of moles using the formula:
moles = volume × concentration
Once you have the number of moles, you can find the molar mass of NaCl (58.44 g/mol) and calculate the grams. In this case, the correct answer is option C) 58.0 grams.
For the second question, to calculate the % w/v of a NaCl solution, we need to use the formula:
% w/v = (mass of solute / volume of solution) × 100
Using the given values, the correct answer is option B) 13.3%.
Explanation:
When dealing with solutions, it's crucial to understand how to calculate the concentration of solutes like NaCl. In the first question, we were given a solution with a concentration of 2.5 M in a volume of 100 ml.
To find the grams of NaCl in the solution, we needed to first calculate the number of moles present in the solution. This was done by multiplying the volume (100 ml) by the concentration (2.5 M) of the solution.
Once we had the number of moles, we then used the molar mass of NaCl (58.44 g/mol) to calculate the grams present in the solution, which turned out to be 58.0 grams.
Moving on to the second question, we were asked to find the % w/v of a NaCl solution made by dissolving 100 grams of NaCl in 750 ml of solution. By utilizing the formula for % w/v, we were able to determine that the solution had a concentration of 13.3%.
Understanding how to calculate the concentration of solutions is fundamental in various scientific fields, especially in chemistry and biology. These calculations allow scientists to accurately determine the properties and behavior of different substances in solution.
By mastering these calculations, you'll be equipped to analyze and work with solutions effectively, contributing to advancements in research and applications across different industries.