Incorrect dilution values per text implications.

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AI Thread Summary
The discussion revolves around calculating the concentration of chromate ions ([CrO4^2-]) in solutions prepared with varying volumes of K2CrO4 and NaNO3. The calculations yield concentrations ranging from 2.4x10^-5M to 3.6x10^-4M, which the poster finds inconsistent with the graph's x-axis values that suggest much higher concentrations. Concerns are raised about the possibility of a typographical error in the graph's labeling, as concentrations above 10M are uncommon. The consensus is that the poster's calculations are correct and that the graph likely contains a mistake. Clarification on the graph's intended scale is needed to resolve the confusion.
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Homework Statement



Volumes of 1, 5, 10 and 15mL .0024M K2CrO4 are added to separate flasks and then filled with enough .25M NaNO3 to make 100mL of solution each. I'm asked to calculate the [CrO4^2-] per flask. I assume that all of the K2CrO4 will dissociate and, since there is only 1mol CrO4^2- per mole of K2CrO4, the [CrO4^2-] = [K2CrO4].

Homework Equations



M1V1 = M2V2 ==> M2 = M1V1/V2

The Attempt at a Solution



My calculations gave me the following values for each flask.

Flask with 1mL K2CrO4: [CrO4^2-] = 2.4x10^-5M

Flask with 5mL K2CrO4: [CrO4^2-] = 1.2x10^-4M

Flask with 10mL K2CrO4: [CrO4^2-] = 2.4x10^-4M

Flask with 15mL K2CrO4: [CrO4^2-] = 3.6x10^-4M

My concern, though, is that the text asks me to graph these values against the corresponding volume of K2CrO4 for each flask but the values of the x-axis ([CrO4^2-]) on the suppplied graph range from 0 to 3.6x10^4 are marked in increments of .2x10^4... Would it seem that this is supposed to be ten-to-the-negative fourths or have I completely missed something?

It seems to me that any concentration of 2000M is a bit steep. Also - why would a decimal be used if it were intended to be expressed in thousands rather than thousandths?

All of my data would fit on the table if it were a typo but with the concentration of the 1mL flask being to the negative 5th I thought I'd see if anyone could help me find the error.

Thank you
 
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Must be a typo. Your approach is correct.

In general concentrations higher than 10M are very rare, highest concentration I can think of is that of pure water - 55.5 M. Concentrated acids can get up to about 17 or 18M.
 
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