How much of a 8 M NaCl solution is required to make 150 ml of 20 mM NaCl?

Question

I need help with this Chemistry molarity problem. Someone please help.

Answer 1

The equation you need is M1V1 = M2V2. This equation is great for any kind of dilution problem. M1 and M2 are the molarities of the initial and final solution (convert the 20 mM into M) and V1 and V2 are the volumes of the initial and final solutions. Ideally, everything should be calculated in liters, but as long as you are consistent with the units, it works out OK.

Answer 2

hi. you're having with the mole idea, I presume. properly, that is amazingly user-friendly. A mole of a chemical substance or element is the atomic weight expressed in grams of the molecule or element. So, a a million M answer of NaCl incorporates the molecular weight of NaCl dissolved in a million liter of water. A 2 molar answer of NaCl incorporates two times the molecular weight dissolved in a million liter of water. a nil.10 M answer will in hardship-free words contain one 10th the molecular weight expressed in grams dissolved into a million liter of water. As I bear in mind, the atomic weights for Na and Cl are 23 and 37. apparently, atomic weight is amazingly previous formed for use lately and that is spoken of as atomic mass. ok, then, same element. So the atomic mass of NaCl = 23 + 37 = 60. So, a million L 0.10 M NaCl could have 6 g NaCl. keep on with? what number grams ought to one hundred fifty mL of a similar answer have? a million,000 mL 0.10 M NaCl contain 6 g So, a million ml " " " " 6/a million,000 g for this reason, one hundred fifty " " " " one hundred fifty x 6/a million,000 ......................................... 900/a million,000 ......................................... 9/10 = 0.ninety g So, your interest is to p.c.. the only volume from the above record for a 2 molar answer which will contain .9 g. properly, b. gained't because it ought to contain 3 x 60 g. ok, enable's discover out how a lot NaCl should be contained in a million mL of a 2 M answer. a million,000 ml = 60 g a million " = 60/a million,000 = 6/one hundred = 0.06 g. in hardship-free words one answer will come close to to that, it truly is can should be., a million.5 mL. regardless of the indisputable fact that it appears that evidently like I have tangled up the decimal element someplace. you hit upon out the position I went incorrect, will you. i have dodne better than purely that, have not I? solid education so that you'll be able to maximum ideas-blowing my operating as in case you've been a instructor. the way in which to study something is to educate it.

Answer 3

initial molarity times the imitial volume equals the final molarity times the final volume. MV=MV so just substitute in and solve for your missing variable. just make sure you convert your units so that they're all the same such as millimoles and moles.

Answer 4

V1x8x1000=150x20---

V1=150x20/8x1000=0.375 ml