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On a spring morning (20 degree C) you fill your tires to a pressure of 2.25 atmo

ID: 1067526 • Letter: O

Question

On a spring morning (20 degree C) you fill your tires to a pressure of 2.25 atmospheres. As you ride along, the tire heats up to 45 degree C from the friction on the road. What is the pressure in your tires now? A gas has a volume of 175 L at 760. torr and 288 K. What is the temperature if the gas volume and pressure are changed to 198 L and 640. torr? A given mass of oxygen at room temperature occupies a volume of 500.0 mL at 1.50 mL) pressure. What will be the pressure if the volume is reduced to 150.0 mL? Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres. will be exerted by 2.500 g of oxygen gas (O_2) when stored at 22 degree C in a 40.0 L cylinder? Consider the following reaction at STP: CuO(s) + H_2(g) rightarrow cu(s) + H_2O(g) If 40.0 g of CuO react with an excess of H_2, how many liters of H_2O will be produced?

Explanation / Answer

2. Intial                                           Final

P1 = 2.25atm                           P2 =

T1    = 20C0 = 20+273 = 293K                    T2   = 45C0   = 45+ 273 = 318K

      P1/T1   = P2/T2

       P2    = P1T2/T1

               = 2.25*318/293 = 2.44atm

3. Intial                                                          Final

   P1 = 760torr                                              P2 = 640torr

   V1   = 175L                                                 V2 = 198L

    T1   = 288K                                                T2 =

                P1V1/T1     =    P2V2/T2

                  T2             = P2V2T1/P1V1

                                   = 640*198*288/760*175   = 274.4K

Initial                                                    Final

P1 = 1.5atm                                          P2 =

V1   = 500ml                                          V2 = 150ml

            P1V1   = P2V2

             P2     = P1V1/V2

                     = 1.5*500/150   = 5atm