48. GO The diffusion constant for the amino acid glycine in water has a value of 1.06 X 10-º m²/s. In a 2.0-cm-long tube with a cross-sectional area of 1.5 × 10-“ m², the mass rate of diffusion is mlt = 4.2 × 10-1ª kg/s, because the glycine concentration is maintained at a value of 8.3 × 10-³ kg/m³ at one end of the tube and at a lower value at the other end. What is the lower concentration?

1. A bicycle pump inflates a tire of volume 565 mL until the gauge pressure is 6.47 bar at a temperature of 21.7°C. (Note: the volume of the tire before and after it is "inflated" is 565 mL. Initially, the tire contains air at ambient atmospheric pressure.) (a) If the barometric pressure is 1.01 bar, what is the absolute pressure in the tire? (b) (c) How many moles of air does the tire contain? What volume of air at 1.01 bar and 21.7°C did the pump transfer?

A light balloon is filled with 397 m3 of helium at atmospheric pressure. (a) At 0°C, the balloon can lift a payload of what mass? kg (b) In the table below, observe that the density of hydrogen is nearly half the density of helium. What load can the balloon lift if filled with hydrogen? | kg Densities of Some Common Substances at Standard Temperature (0°C) and Pressure (Atmospheric) Substance p(kg/m³) p(kg/m3) Substance 0.917 X 10 7.86 X 10 Air 1.29 Ice Aluminum 2.70 X 10 Iron Benzene 0.879 X 103 Lead 11.3 X 10 Copper 8.92 X 103 Mercury 13.6 X 103 Ethyl alcohol Fresh water 0.806 X 10% Oak 0.710 X 10 1.00 X 10 Oxygen gas 1.43 Glycerin 1.26 X 103 Pine 0.373 X 103 19.3 X 10 1.79 X 10-1 21.4 X 10 1.03 X 10 10.5 X 103 Gold Platinum Helium gas Seawater Hydrogen gas 8.99 X 10-2 Silver

A hot air balloon uses the principle of buoyancy to create lift. By making the air inside the balloon less dense then the surrounding air, the balloon is able to lift objects many times its own weight. A large hot air balloon has a maximum balloon volume of 2090 m3. a.  If the air temperature in the balloon is 54 °C, how much additional mass, in kilograms, can the balloon lift? Assume the molar mass of air is 28.97 g/mol, the air density is 1.20 kg/m3, and the air pressure is 1 atm.

When air expands adiabatically (without gaining or losing heat), its pressure P and volume V are related by the equation PV14 = Cwhere C is a constant. Suppose that at a certain instant the volume is 670 cubic centimeters and the pressure is 99 kPa and is decreasing at a rate of 7 kPa/minute. At what rate in cubic centimeters per minute is the volume increasing at this instant? cm3 min (Pa stands for Pascal -- it is equivalent to one Newton/(meter squared); kPa is a kiloPascal or 1000 Pascals. )