Key Chemistry Formulas and Constants

1 mole

6.02 * 10^23 molecules

1 mole @ STP

22.4 L

1 atm

760 mmHg

1 g

6.02 * 10^23 amu

K

°C + 273

Dilution Equation

m1v1 = m2v2

Ideal Gas Law

PV = nRT

MCAT Heat Equation

q = mCAT = mC(tf - ti)

q=-q

Density

mass/volume

1 molar

1 mole/L

molar mass equation

m=m (mass) /n (moles)

Total Pressure Equation

Pt = P1+P2+P3...

PT= P1V1 + P1V! + P1V1/ V2

Pressure-Volume equation

P1V1=P2V2

Pressure-Volume and Temp equation

P1V1/T1 =P2V2/T2

Steps in a Stoichiometric Calculation

balanced equation, convert, mole ratio, convert to units desired

molar mass

the mass in grams of one mole of a substance

Molarity equation

moles of solute/liters of solution

What is gas pressure?

collision force of gas particles on a surface

What holds the suction cup down?

When the suction cup is placed on a surface, trapped air is sealed under it. When the handle is activated, the space (volume) under the cup enlarges, and the trapped air collides less with the bottom of the cup, resulting in less upward force and stronger exterior collisions.

Pressure relating to a straw?

When a person sucks a straw, air collides with the surface creating a dynamic with water pushing against the plastic

As volume increases, pressure

decreases

As volume decreases, pressure

increases

As temperature increases, volume

increases (direct relationship)

As temperature increases, pressure

increases (direct relationship)

refrigerant

a material used to cool an area or an object lower than room temp

How does a refrigerator work

it transfers thermal energy from the cool air inside of it to the warm air in the kitchen. It uses a refrigerant, a substance with a low boiling point that changes between liquid and gaseous states, making the food donate heat to everything else

How does air conditioner work

The refrigeration cycle involves several key steps: Evaporation, where liquid refrigerant absorbs heat and turns into a gas, cooling the surrounding air; Condensation, where the hot gas releases heat and condenses back into liquid; and Expansion, where the expansion valve reduces the pressure and temperature of the liquid, preparing it for the next cycle.

Heat flow of stove

The heat from a stove is transferred to objects by conduction and convection. Conduction occurs when a pan or pot is in direct contact with the stove's burner, transferring heat through the metal. Convection involves heated air rising from the stove, transferring heat to the pot or pan.

Endothermic

Absorbs heat

Exothermic

Releases heat

Endothermic example

cold pack, air conditioner uses endothermic example to absorb warmth and make room cooler

Exothermic example

hot hands (hand warmers: crystals release heat to make hands warm), combustion

specific heat capacity

the energy required to raise the temperature of one gram of a substance by one degree Celsius

Conduction

Conduction is the transfer of energy, typically heat or electricity, through direct contact between objects or particles; Thermal energy passed along when warmed up particles heat up neighboring particles.

Conduction is primarily for

solids and liquids (stationary matter)

Convection

warmed up particles traveling with thermal energy

Convection is primarily for

liquids and gases

Infared radiation

heat transfer at the speed of light as a wave of energy

Examples of conduction

Pan on stove, hot chocolate and spoon, metal rod warmed by the hand

examples of infared radiation

the heat from the sun, a fire, a radiator, or even a warm sidewalk

examples of convection

Boiling water - The heat passes from the burner into the pot, heating the water at the bottom.

Flames of fire, air conditioner

percent yield calculation

Actual yield/ Theoretical yield x 100

Actual yield calculation

Actual yield= (%yield/ 100) * Theoretical yield

Mixing substances: final temperature

Tf= MCTi + MCTi/ MC + MC