# Finding Concentration of a Standard Solution using % purity ?

• nerdy_hottie
In summary, the conversation discusses finding the concentration in ppm of a diluted Fe2+ solution using the information of the starting solution. The attempt at a solution calculates 78.56 ppm, but it is questioned because it is outside the range of the spectrometer used and does not take into account the 99.7% purity of the solution. The solution is to first convert the mg/L to ppm, and then multiply by 99.7% to find the actual concentration of Fe2+ in the solution.
nerdy_hottie

## Homework Statement

I need to know the concentration in ppm of a standard Fe2+ solution. (diluted)
Here is the data I have.
I have 0.1964 g of Fe solution
the purity is 99.7%

The original solution was the above # of g in 250ml water.
10ml of this was then pipetted into a 100ml volumetric flask and diluted.
I have to find the concentration in ppm of this diluted solution using the info from the starting solution.

## Homework Equations

Don't think there are any. Just need logic to figure it out, of which I am limited in.

## The Attempt at a Solution

196.4mg/0.250L
=785.6 mg/L
*(10ml/100ml)
=78.56 ppm

This is what I have, but I don't think it's right because 78.56 ppm is not in the range of the spectrometer we used. Also, I didn't use the 99.7% purity anywhere.

Thanks.

nerdy_hottie said:

## Homework Statement

I need to know the concentration in ppm of a standard Fe2+ solution. (diluted)
Here is the data I have.
I have 0.1964 g of Fe solution
the purity is 99.7%

The original solution was the above # of g in 250ml water.
10ml of this was then pipetted into a 100ml volumetric flask and diluted.
I have to find the concentration in ppm of this diluted solution using the info from the starting solution.

## Homework Equations

Don't think there are any. Just need logic to figure it out, of which I am limited in.

## The Attempt at a Solution

196.4mg/0.250L
=785.6 mg/L
*(10ml/100ml)
=78.56 ppm

This is what I have, but I don't think it's right because 78.56 ppm is not in the range of the spectrometer we used. Also, I didn't use the 99.7% purity anywhere.

Thanks.

Actually mg/ml is ppm - work it out.

Then you'll have the ppm of the stuff you put in the flask.

But only 99.7% of the stuff you put there is the Fe you are interested in.
So how many ppm is that?

Simples.

Assuming you have reported the question entirely because I am a bit puzzled about what ppm of "Fe" means, (you didn't weigh out iron filings, does your source give some convention?)

Last edited:

## What is the concept of finding concentration of a standard solution using % purity?

The concept involves determining the concentration of a solution by taking into account the percentage of the pure substance present in the solution. This is useful when the substance is not available in a pure form and the impurities can affect the accuracy of the measurement.

## Why is it important to know the concentration of a standard solution?

The concentration of a standard solution is important for various reasons such as performing accurate experiments, determining the amount of reactants needed for a reaction, and ensuring the quality of the solution. It is also necessary for the conversion of units and for comparing different solutions.

## What are the steps involved in finding the concentration of a standard solution using % purity?

The steps generally involve measuring the volume and mass of the solution, determining the percentage of purity of the substance, and using mathematical formulas to calculate the concentration. This may vary depending on the specific experiment and the substance being used.

## What factors can affect the accuracy of the concentration measurement?

The accuracy of the concentration measurement can be affected by various factors such as human error in measurement, contamination of the solution, incomplete dissolution of the substance, and changes in temperature or pressure. It is important to minimize these factors to obtain an accurate result.

## Are there any alternative methods for finding the concentration of a standard solution?

Yes, there are alternative methods such as using a calibration curve, titration, and spectrophotometry. These methods may be more accurate and precise in certain situations, but they also require specific equipment and expertise. The method of using % purity is a simpler and more common approach for finding the concentration of a standard solution.

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