molarity – a molarity of a solution is the # of moles of solute per liter of a solvent

solvent– a substance that dissolves another to form a solution: Water is a solvent for sugar. solute– the substance dissolved in a given solution

Fahrenheit to Celsius ----- C = F – 32 x 5/9

Celsius to Fahrenheit ----- F = C x 5/9 + 32

Celsius to Kelvin ----- C = K - 273

Kelvin to Celsius ----- K = C + 273

Early scientists understood the difference between “hot” and “cold,” but they had no method to quantify varying degrees of heat until the seventeenth century. In 1597, Italian astronomer Galileo invented a simple water thermo scope, a device that consisted of a long glass tube inverted in a sealed jar that containing both air and water. When the jar was heated, the air expanded and pushed the liquid up the tube. The water level in the tube could be compared at different temperatures to show relative changes as heat was added or removed. However, the thermo scope lacked an easy way to directly quantify temperature.

Several years later, the Italian physician and inventor Santorio improved Galileo’s design by adding a numerical scale to the thermoscope. These early thermoscopes led to the development of the fluid-filled thermometers commonly used today. Modern thermometers operate based on the tendency of some fluids to expand when heated. As the fluid inside a thermometer absorbs heat, it expands, occupying a greater volume and forcing the fluid level inside the tube to rise. When the fluid is cooled, it contracts, occupying a smaller volume and causing the fluid level to fall.

Temperature is a measure of the amount of heat energy possessed by an object. Because temperature is a relative measurement, scales based on reference points must be used to accurately measure temperature. There are three main scales commonly used in the world today to measure temperature: the Fahrenheit (°F) scale, the Celsius (°C) scale, and the Kelvin (K) scale.

Each of these scales uses a different set of divisions based on different reference points, as described in detail below.

FahrenheitDaniel Gabriel Fahrenheit (1686-1736) was a German physicist who is credited with the invention of the alcohol thermometer in 1709 and the mercury thermometer in 1714. The Fahrenheit temperature scale was developed in 1724.

Celsius Anders Celsius (1701-1744) was a Swedish astronomer credited with the invention of the centigrade scale in 1742. Celsius divided the difference in temperature between the freezing and boiling points of water into 100 degrees (thus the name centi, meaning one hundred, and grade, meaning degrees). After Celsius's death, the centigrade scale was renamed the Celsius scale and the freezing point of water was set at 0°C and the boiling point of water at 100°C. The Celsius scale takes precedence over the Fahrenheit scale in scientific research because it is more compatible with the base ten format of the International System (SI) of metric measurement.

Kelvin Lord William Kelvin (1824-1907) was a Scottish physicist who devised the Kelvin (K) scale in 1854. The Kelvin scale is based on the idea of absolute zero, the theoretical temperature at which all molecular motion stops and no discernable energy can be detected The Kelvin scale, like the Celsius scale, is a standard SI unit of measurement used commonly in scientific measurements. Since there are no negative numbers on the Kelvin scale (because theoretically nothing can be colder than absolute zero), it is very convenient to use Kelvins when measuring extremely low temperatures in scientific research.

Robert Boyle (1600's)

Correlates pressure and volume when dealing with gases

Pressure and volume are inversely proportional

•There are several units that can be used for pressure: psi, Pascal's, atm’s, etc…

•We will use atm’s for practice

•1atm = air pressure at sea level

P1V1 = P2V2

Pressure 1 x volume 1 = pressure 2 x volume 2

EX: You have air bubbles in your bones because you ascended too quickly from scuba diving. Each bubble has a volume of 0.2mL. The pressure in your bones is 1.2atm. In order for the bubbles to dissolve back into your blood, their volume must be reduced to 0.05mL. To do this, you enter a hyperbaric chamber. What must you set the pressure gauge to?

1.2 x 0.2 = x times .05 .24 = .05x .05 .05 4.8atm = X

V1 V2

T1 T2=

•discovered by Jacques Charles

•correlates a gas volume with temperature

•for gases… temperature and volume are directly proportional

A hot air balloon statrs to sink when its volume sinks to 10,000 mL of air. If the hot air balloon stats to sink and the temperature is 15̊ celsius, causing you to increase the temperature to 293 Kelvin.What will your new volume be?

10000 X288 293K

=

2930000288

288x288= = 10173.6mL

10000 x 293=2930000