Question

Hydrogen cyanide, HCN, is a poisonous gas. The lethal dose is approximately 300. mg HCN per kilogram of air when inhaled. The density of air at 26 ∘C is 0.00118 g/cm3.

part a.

Calculate the amount of HCN that gives the lethal dose in a small laboratory room measuring 12.0 ft×15.0 ft×8.60ft .

Express your answer to three significant figures and include the appropriate units.

part B

Consider the formation of HCN by the reaction of NaCN (sodium cyanide) with an acid such as H2SO4 (sulfuric acid):

2NaCN(s)+H2SO4(aq)→Na2SO4(aq)+2HCN(g)

What mass of NaCN gives the lethal dose in the room?

Express your answer to three significant figures and include the appropriate units.

part C

HCN forms when synthetic fibers containing Orlon^® or Acrilan^® burn. Acrilan^® has an empirical formula of CH2CHCN, so HCN is 50.9% of the formula by mass. A rug in the laboratory measures 12.0× 15.0 ft and contains 30.0 oz of Acrilan^® fibers per square yard of carpet. If the rug burns, what mass of HCN will be generated in the room? Assume that the yield of HCN from the fibers is 20.0% and that the carpet is 43.0 % consumed.

Express your answer to three significant figures and include the appropriate units.

Answer 1

Answer 2

1- The given lethal dose of HCN = approximately 300. mg per kilogram of air

Now the given density of air = 0.00118 g/cm3.

Thus the volume of 1 kg air = mass / density

= 1 kg / 0.00118 g/cm3.

= 1000 g / 0.00118 g/cm3.

= 847457 cm3

i.e now the lethal dose of HCN = 300. mg per kilogram of air = 300. mg per 847457 cm3 of air

Now the given volume measurements of room = 12.0 ft *15.0 ft × 8.60 ft

= .1548‬ ft3

Now convert ft into cm = (1548‬ * 30.48) cm3

= 47183.04‬ cm3

Thus the  lethal dose of HCN in  47183.04‬ cm3 volume of air will be= (300. mg / 847457 cm3) *  47183.04‬ cm3

= 16.7 mg

2-

The given reaction is

2NaCN(s) + H2SO4(aq) → Na2SO4(aq) + 2HCN(g)

That means we will get 2 moles of HCN from 2 moles of NaCN

If we write it in terms of mass, then mass of  2 moles of HCN = mole * molar mass

= 2 * 27.0253 g/mol

= 54.0506‬ g

= 54050.6‬ mg

Similarly mass of  2 moles of NaCN = mole * molar mass

= 2 * 49.0072 g/mol

= 98.0144‬‬ g

= 98014.4‬‬ mg

That means we will get 54050.6‬ mg of HCN from 98014.4‬‬ mg NaCN

Our lethal amount of HCN in room = 16.7 mg

Then we will get 16.7‬ mg of HCN from = 98014.4‬‬ mg NaCN / 54050.6‬ mg of HCN * 16.7‬ mg of HCN

= 30.28 mg NaCN

3-

For this ques plz check the units of measurements you have provided. They dont seem to be write and rewrite the ques properly please. It is incomprehensible