Arick+N

Assignment 2: On class on friday when we used the liquid nitrogen with the marshmellow, the marshmellow shrunk to a much smaller size. This is an example of __Charle's law__ because it states when temperature decreases, volume decreases. This is apparent because the volume of the marshmellow decreased when the temperature around it decreased. When you squeeze a stress ball, it's size gets smaller but it gets more difficult to squeeze. This is an example of __Boyle's law__, which states when volume increases, pressure decreases and vice versa. When the ball shrinks as you squeeze it, to volume decreases and thus the pressure must increase, which is why it gets harder to squeeze. In a hot air balloon, when the heat rises into the balloon, it firms up due to the increase in pressure. This illustrates __Gay-Lussacs law__ which states when temperature increases, pressure also increases and the opposite. As heat enters the balloon, temperature increases as well as pressure.

Assignment 4: Water is the only natural substance that can be found on earth in each liquid, solid, and gaseous states under normal conditions. It occurs in liquid form between 0 and 100 degrees celsius, freezes to solid below 0 degrees celsius, and boils to gaseous when over 100. Waters weight varies in different conditions. At 32 degrees farenheight it is about 62.4 pounds per cubic foot, whereas it is 61.9 pounds per cubic foot at 100 degrees farenheight. Water has a high specific heat, which means it takes more energy to put into water in order to change it's temperature relative to other substances. Water has a slightly lower density than other molecules: 1g/ml at 4 degrees celsius. Density is the amount of mass per unit of volume, which means it is how much of the substance is present. Water is also a universal solvent, which allows it to dissolve many other molecules within itself.

"Physical Properties of Water." //PhysicalGeography.net Welcome Page//. 22 Feb. 2010. []

Assignment 6:

Concentration: Increasing the concentration of the reactants means that more reactants are present, which will cause them to collide and react more often. An example of this would be with "Elephant Toothpaste", where the more hydrogen peroxide added to the potassium iodide, the faster the reaction between the two occurs.

Temperature: When tem:perature in a reaction is increased, it causes an increase in the average kinetic energy of the molecules which makes them move faster and collide/ react more often. An example of this would be using a glowstick, where when you snap the glowstick, the temperature incerases and thus the reaction speeds up and the molecules produce light.

Catalysts: Catalysts speed up reactions by decreasing the required activation energy for the reaction to occur. They do this by increasing the number of times the molecules collide. An example of this would be the decomposition of hydrogen peroxide using manganese oxide. Whisat the manganese oxide does is lower the activation energy so the hydrogen peroxide breaks up faster.

Surface Area: More surface area allows the reactants to cover more of each other and thus speeding up the reaction. When a gallon of gasoline is in a barrel, it will burn slower than if it was dumped out. This is because when it is dumped it has a wider range for the fire to spread and so it burns faster.

Assignment 7:

A simple example of equillibrium is when water is contained and begins turning into vapor. When it reaches the most vapor it can in the container, it is at equillibrium. This means that the water is still turning into vapor and vapor to liquid, but it happens at the same rate so there is no net change while the reaction is still occurring.

Assignment 8:

At equillibrium the concentrations must remain the same because the reactions occur at the same rate, so neither side gains or loses concentration. Although no concentrations seem to change, the reactions are still occurring, but at a pace where it seems as it is still. The product concentrations in an equillibrium are written in brackets, equillibrium positions are written over the concentrations of the reactants in brackets. 1. H2(g) + I2(g) --- 2HI(g) K= __[HI]2__ [H2] [I2] 2. N2(g) + O2(g) --- 2NO(g) K__= [NO]2__ [N2] [O2] 3. Br2(g) --- 2Br(g) K= __[Br] 2__ [Br2]

Homogeneous example: C2H2(g) + 2Br2(g) --- C2H2Br4(g) K= __[C2H2Br4]__ [C2H2] [Br2]2

Heterogenous example: PCl5(s) --- PCl3(l) + Cl2(g) K= [Cl2]