# chemistry

posted by .

A chemist has 12.0 M HBr and would like to use it to make 500.0 mL of 3.5 M HBr. describe how she should do this

• chemistry -

mL x M = mL x M
mL x 12.0 = 500 x 3.5
mL = you can do it---about 60 mL or so.

The reason I worked it through is to show you what NOT to do. You DON'T use 60 mL of the concd soln (or whatever the number turns out to be) and add 500 mL of water. Instead, you take 60 (or whatever) and add to water to make a total of 500 mL of solution. On an exam, that is the tricky part. The prof will want to see that you have written that the total solution is 600 mL, not 60 mL added to 540 mL because volumes are not additive and in accurate work you may not assume they are.

• chemistry -

1.5 x 10(10) mL

## Similar Questions

1. ### Chemistry

What volume of 14.1M HBr is required to make 250mL of 1.25M HBr solution by dilution with water?
2. ### Chemistry

If a chemist has a stock solution of HBr that is 10.0 M and would like to make 450.0 mL of 3.0 M HBr, how would he or she do it?
3. ### Chemistry

For the following reaction, Kp = 3.5 104 at 1495 K. H2(g) + Br2(g) 2 HBr(g) What is the value of Kp for the following reactions at 1495 K?
4. ### Chem-E / Chemistry

Calculate the rate of heat required to bring 1.80mol/hr of HBr gas from 37.0 C to 434.0C at atmospheric pressure (Heat capacity of HBr is described by eq.) Cp (kJ/mol * C) = a + bT + cT^2 + dt^3 T is in C and HBr - a = 2.910x10^-2, …
5. ### chemistry

the equilibrium constant for the synthesis of HBr(g0 from hydrogen and bromine gas is 2.18*10 exponent 6 at 730 degrees celcius.if 3.75 mol of HBr(g) is put into a 15L reaction vessel,calculate the concentration of H2,Br2 and HBr at …
6. ### chemistry

Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.180 M pyridine, C5H5N(aq) with 0.180 M HBr(aq): 1)before addition of any HBr 2)after addition of 12.5 ml of HBr: 3)after addition of 16 ml of HBr: 4)after …
7. ### Chemistry

1. Calculate the pH for each of the following cases in the titration of 25.0 mL of 0.240 M pyridine, C5H5N(aq) with 0.240 M HBr(aq): (a) before addition of any HBr (b) after addition of 12.5 mL of HBr (c) after addition of 22.0 mL …
8. ### Chemistry

Letâ€™s assume you have 250 ml of a 1.3M KOH solution and you want to neutralize it with the acid HBr. It takes 350 ml of the HBr solution to do so. What must have been the molarity of the HBr solution?
9. ### Chemistry

Calculate the pH of the the solution that results from titrating 50 mL of 0.6 M NaOCl(aq) with 0.3 M HBr At 0.00 mL of HBr: At 70 mL of HBr: At 100 mL HBr: At 120 mL of HBr
10. ### Chemistry

A 38.5 mL sample of HBr is titrated with 112 mL of 1.05 mol/L KOH. The density of the HBr solution is 1.75 g/mL. Calculate the percentage by mass of the HBr in the sample. How come we don't use density*volume to find the moles of HBr?

More Similar Questions