Inhaled Hydrogen Cyanide
help with chemical equations pls?..tried solving it..but i failed :l?
Hydrogen cyanide is a poisonous gas. The lethal dose is approximately 300 mg HCN per kilogram of air when inhaled.
a.Calculate the amount of HCN that gives the lethal dose in a small laboratory room measuring 12 by 15 by 8.0 ft. The density of air at 26 degrees Celsius is 0.00118 g/cm3.
b.If the HCN is formed by reaction of NaCN with an acid such as H2SO4, what mass of NaCN gives the lethal dose in the room?
2NaCN(s) + H2SO4 –> Na2SO4 (aq) + 2HCN (g)
c.HCN forms when synthetic fibers containing Orion or Acrilan burn. Acrilan has an empirical formula of CH2CHCN, so HCN is 50.9% of the formula mass. A rug measures 12 by 15 ft. and contains 30 oz of Acrilan fibers per square yard of carpet. If the rug burns, will a lethal dose of HCN be generated in the room? Assume that the yield of HCN from the fibers is 20% and that carpet is 50% consumed.
hope you can help me out..super thanks 
Lancenigo di Villorba (TV), Italy
You wrote that Hydrogen Cyanide results a poisonous gas having Lethal Dose like 300 ppm (ppm are million-th parts).
QUESTION a)
The room you describe contains a volume like
12 X 15 X 8 = 1440 cubic-feet = 47 cubic-meters
which contains air stading at condition assuring a Ponderal Density like
1.18 g / Liter = 1180 g / cubic-meters
Then, the air mass present in the room is
1180 * 47 = 55700 grams of gas
then the required amount to reach Lethal Dose is
55700 * 300E-6 = 16.7 grams of HCN
QUESTION b)
Since the HCN comes from sulphuric bath, you look for the mass amount of NaCN required to leaves up HCN. Then the reaction follows
2 NaCN(s) + H2SO4(aq) –> Na2SO4(aq) + 2 HCN(g)
stating a STOICHIOMETRIC RATIO LIKE
NaCN : HCN = 2 : 2
assuring that ONE MOLE OF Hydrogen Cyanide COMES FROM ONE MOLE OF Sodium Cyanide. Then, mathematically
(16.7 / (1 + 12 + 14)) = (x / (23 + 12 + 14))
the mass amount you need is
x = 16.7 * 49 / 27 = 30.3 grams of NaCN
QUESTION N.3)
Acrylan is a synthetic clothes made by ACRYLONITRILE (e.g. CH2CH=CN) bearing HCN in feature of 50.9%.
The rug burned the 50% of its whole surface, e.g. 50% of the whole surface 12 X 15 square-feet
0.50 X 12 X 15 = 90 square-feets = 9.2 square-meters
This area has a weight corresponding to
30 * 9.2 / (0.914)^2 = 330 oz = 9340 grams of rug
This mass leaven off a corresponding amount of HCN by 20% of theoretical yield expressed in 50.9%
20% * 50.9% * 9340 = 950 grams of HCN
Yes, IT OVERTHROWS THE LETHAL DOSE!
I hope this helps you.