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Calculate the molarity of a solution prepared by dissolving 12.6 g of na2cro4 in enough water to produce a solution with a volume of 630. ml

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midknight9
First we need to calculate the molar mass of [tex] Na_{2} CrO_{4} [/tex]:

Na: 22.99g * 2 = 45.98g

Cr: 51.996g

O: 15.999g * 4 = 63.996g

Then add all of them together:

[tex]45.98g+51.996g+63.996g=161.97g[/tex]

Now we know the molar mass of [tex] Na_{2} CrO_{4} [/tex] is 161.97g.

We are given the amount of grams used in the solution. So let's find how many moles that were used:

[tex] \frac{1mole}{161.97g}* \frac{12.6g}{1}=0.078mol [/tex]

We are asked to calculate the molarity, and we know the molarity formula is as follows:

[tex]Molarity= \frac{#moles}{Liters} [/tex]

We just calculated the number of moles that were used, and we are given the amount of solution (in mL, but we can convert 630 mL to 0.63 L by dividing by 1000 since there are 1000 mL in 1 L). So let's plug in the values to calculate for molarity:

[tex]Molarity= \frac{0.078mol}{0.63L}=0.12M [/tex]

So now we know that the molarity of the solution is 0.12 M.
CintiaSalazar

Considering the definition of molarity, the molarity of the solution is 0.12 [tex]\frac{moles}{liter}[/tex].

It is neccesary to know that molarity reflects the concentration of a solution, indicating the number of moles of solute that appear dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution.

[tex]molarity=\frac{number of moles of solute}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

In this case, first you must know that the molar mass (that is, the mass of a mole of a substance, which can be an element or a compound)  of Na₂CrO₄ (solute) is 161.97 g. So the number of moles of solute can be calculated as:

[tex]12.6 gx\frac{1 mole}{161.97 g}[/tex]= 0.078 moles

Being the volume 630 mL = 0.630 L (where 1000 mL = 1 L), the molarity can be calculated as:

[tex]molarity=\frac{0.078 moles}{0.630 L}[/tex]

molarity= 0.12 [tex]\frac{moles}{liter}[/tex]

Finally, the molarity of the solution is 0.12 [tex]\frac{moles}{liter}[/tex]

Learn more about molarity with this example: brainly.com/question/15406534?referrer=searchResults

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