a 31.9g sample of HF is dissolved in water to give 2.0x10e2 mL of solution. The concentration of the solution is?
I think it is 8.0M ?
2006-11-30 01:29:23 · 3 answers · asked by steven11111958 1 in Science & Mathematics ➔ Chemistry
31.9 grams of HF is 31.9g/20.01 g/mole = 1.59 moles
2.0E2 mL is 200 milliliters
(1.59 moles/200 mL) * (1000 mL/liter) = 7.97 moles/liter = 7.97M
So, considering significant digits, your answer of 8.0M is correct.'
BTW, travelling gardener -- most chemists do NOT work in ppm.
2006-11-30 01:35:06 · answer #1 · answered by Dave_Stark 7 · 0⤊ 0⤋
the concentration in a liter is 31.9/0.2 = 159.5g/L as 2*10^2 = 0.2L
the molecular weight of HF = 20
so the molarity is 7.95 M near 8
Please verify
2006-11-30 01:40:57 · answer #2 · answered by maussy 7 · 0⤊ 0⤋
I hope you are right, but shouldn't the concentration be listed in ppm as most concentrations are for simplicity?
2006-11-30 01:31:26 · answer #3 · answered by Anonymous · 0⤊ 0⤋