Some rocket engines use a mixture of hydrazine, N 2 H 4, and hydrogen peroxide, H 2 O 2, as the propellant according to the following equation: N 2 H 4 + 2H 2 O 2  N 2 + 4H 2 O Which is the limiting reactant in this reaction when 100.g of N 2 H 4 is mixed with 100.g of H 2 O 2 ?

 Has indefinite volume and shape  A fluid (particles slide past each other)  Low density- 1/1000 that of a solid or liquid  Highly compressible  Can spontaneously diffuse and effuse  Effusion- ability of a gas to pass through tiny openings

 Based on the idea that particles of matter are always in motion  theory explains behavior of gases

 Gases consist of large numbers of tiny articles that are far apart relative to their size.  Collisions between gas particles and between particles and container walls are elastic collisions.  Gas particles are in continuous, rapid, random motion.  There are no forces of attraction or repulsion between gas particles.  The average kinetic energy of gas particles depends on the temperature of the gas.

 Pressure  Volume  Temperature  Number of particles

 Force per unit area  Measurement of the number of collisions against the walls of a container  Units: atmosphere (atm), torr, mm Hg, kilopascal (kPa) 1atm= 760 torr= 760 mmHg= kPa

 The amount of space taken up by a gas  Units: cubic centimeters (cm 3 ), milliliters (mL), liters (L) 1cm 3 = 1mL 1000mL= 1L  As volume increases, the number of collisions between molecules decreases  As volume decreases, the number of collisions between molecules increases

 Measurement of the average kinetic energy  Units: Celsius (°C), Kelvin (K) K= °C  As temperature increases, molecules move faster, leading to more collisions.  As temperature decreases, molecules move slower, leading to fewer collisions.

 Standard Temperature and Pressure  0°C, 1atm  At STP, 1 mol of an ideal gas has a volume of 22.4L

 Unit: mole (mol)  Increasing the number of molecules means less space between molecules, leading to more collisions.  Decreasing the number of molecules means more space between molecules, leading to fewer collisions.

 Why does a tire appear fully inflated during day with warm weather and deflated during days with cold weather? Explain in terms of kinetic molecular theory.