Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1) Wachusetts reservoir holds 2.46*10^11 liters of drinking water. An industrial

ID: 496839 • Letter: 1

Question

1) Wachusetts reservoir holds 2.46*10^11 liters of drinking water. An industrial accident has led to the spill of 7.5* 10^3 kg of potassium cyanide into the reservoir generating the toxic product of hydrogen cyanide

KCN+H2O-----> HCN+KOH

a) What is the concentration in w/v %

b)What is the concentration in ppm

c) The minimun LD50 is 50ppm. What volume of contaminated water would a 67 kg adult need to drink to reachthis level. Assume that the density of water is 1.00 g/mL.

d) What volume of contaminated water would a 12 kg child need to drink to reach this level?

Explanation / Answer

Q1.

a)

simply:

w/v*100% --> mass/volume * 100%:

w/v% = (7.5*10^3)/(2.46*10^11) * 100% = 0.00000304878 w/v %

b)

ppm --> mg / L

mg -->7.5*10^3 kgrams --> 7.5*10^6 grams --> 7.5*10^9 milligrams -->

ppm = (7.5*10^9)/ ( 2.46*10^11)

ppm = 0.03048

c)

he requires:

assume 67 kg --> 67000

0.03048 --> 67/0.03048 = 2198 Liters required

d)

similar:

12/67* 2198 = 393.67L