# Ap Chemistry

posted by .

A perchloric acid solution is composed of 168.75 g of perchloric acid and 81.25 mL of pure water. What is the percent by mass of the perchloric acid solution? The density of
water is 1.000 g/mL.

When I did this part I got 67.5%
But, I am having trouble with the secind part.

The density of the above perchloric acid solution is 1.138 g/mL. What is the molarity of the perchloric acid solution?

I know molarity is moles solute/liter of solution, but how do i find that from %mass? please help if you can!! Thanks!

• Ap Chemistry -

You have 67.5 g HClO4 in 100 g soln.
Convert 67.5 g HClO4 to moles.
Using the density, convert 100 g soln to mL, then M = moles/L.

• Ap Chemistry -

:) Thanks you so much! :)

## Similar Questions

A perchloric acid solution is composed of 168.75 g of perchloric acid and 81.25 mL of pure water. What is the percent by mass of the perchloric acid solution?
2. ### Chemistry-help needed

Posted by candy on Monday, March 28, 2011 at 3:15pm. 0.3g of clotrimazole (C22H17ClN2) was dissolved in 80ml of anhydrous acetic acid. This was titrated with 0.1M perchloric acid using 0.3ml of naphtholbenzein as indicator until the …
3. ### chemistry - help

0.3g of clotrimazole (C22H17ClN2) was dissolved in 80ml of anhydrous acetic acid. This was titrated with 0.1M perchloric acid using 0.3ml of naphtholbenzein as indicator until the colour changes from brownish-yellow to green. 1ml of …
4. ### Chemistry-help needed

0.3g of clotrimazole (C22H17ClN2) was dissolved in 80ml of anhydrous acetic acid. This was titrated with 0.1M perchloric acid using 0.3ml of naphtholbenzein as indicator until the colour changes from brownish-yellow to green. 1ml of …
5. ### chemistry

write the formula of each acid and identify each as a diprotic, a triprotic, or a monoprotic acid sulfuric acid,perchloric acid,phosphoric acid,hydrofluoric acid,acetic acid
6. ### Chemistry

a stock solution of perchloric acid is 75.5% perchloric acid and has a density of 1.67g/ml. What is the molarity of the solution?
7. ### chemistry

A 23.4 mL sample of 0.300 M trimethylamine, (CH3)3N, is titrated with 0.399 M perchloric acid. After adding 6.67 mL of perchloric acid, the pH is
8. ### chemistry

A buffer solution contains 0.283 M hypochlorous acid and 0.456 M potassium hypochlorite. If 0.0464 moles of perchloric acid are added to 225 ml of this buffer, what is the pH of the resulting solution ?
9. ### Chemistry

Perchloric acid, HClO4, is a strong acid. What are the pH values of the following solutions: a) 3 M perchloric acid b) 0.1 M perchloric acid c) 0.001234 M perchloric acid d) 10-5 M perchloric acid e) 10-9 M perchloric acid is the pH …
10. ### Chemistry

How many grams of perchloric acid are dissolved into 3.86 L of water, if the pH of the solution is 4.03.

More Similar Questions