basic chem

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Homework #4 - Chapter 5 gases

1. 32.42 mol Gas A, 28.15 mol Gas B, and 19.69 mol Gas C are in a 1799 L chamber at STP. What is the partial pressure of Gas B (in atm)?

2. Ammonia is produced industrially at high temperatures and pressures. What is the density of ammonia gas at 550 °C and 245 atm?

3. If 0.598 mole of N2, 0.153 mol O2 and 0.079 mol CO2 are exhaled into a ballon, what volume would the balloon occupy at STP?

4. A small research submarine with a volume of 1.2 x 105 L has an internal pressure of 1.0 atm and an internal temperature of 15° C. If the submarine descends to a depth where the pressure is 150 atm and the temperature is 3°C, what will the volume of the gas inside be if the hull of the submarine breaks?

5. If divers rise too quickly from a deep dive, they get a condition called “the bends” which is caused by the expansion of very small nitrogen bubbles in the blood due to decreased pressure. If the initial volume of the bubbles in a diver’s blood is 15 mL and the initial pressure is 12.75 atm, what is the volume of the bubbles when the diver has surfaced to 1.00 atm pressure?

6. The  gill  is  an  obscure  unit  of  volume.  If  some  H2(g)  has  a  volume  of  17.4  gills  at  100°F,   what  volume  would  it  have  if  the  T  were  reduced  to  0°F,  assuming  that  its  pressure   stayed  constant?  

                7. A  convenient  lab  source  of  high  purity  O2  is  the  decomposition  of  permanganate  at  230C      

  ______KMnO4(s)  à  ______K2MnO4  +  ______MnO2  +  ______O2  

  Suppose  3.41  L  oxygen  is  needed  at  atmospheric  pressure  (1  atm)  and  a  temperature  of   20°C.  What  volume  of  oxygen  should  be  collected  at  230°C  and  the  same  P  to  give  this   volume  when  cooled?  

                         

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8. The  density  of  an  unknown  gas  is  1.23  g/L  at  0C  and  1atm.  What  is  the  molecular  mass   of  the  gas?  

                        9. Place  the  following  gases  in  order  of  increasing  average  molecular  speed  at  25C:  Ar,  

CH4,  N2,  CH2F2.                 10. A  gas  mixture  contain  4.5  mol  Br2  and  33.1  molF2  

a. Compute  the  mole  fraction  of  Br2  in  the  mixture   b. The  mixture  is  heated  to  150C  and  starts  to  react  to  give  BrF5,  at  a  certain  point  

in  the  reaction,  2.2  mol  BrF5  is  present.  Determine  the  mole  fraction  to  Br2  in  the   mixture  at  that  point.