Acids and Bases: 1. Be able to identify both the Brønsted–Lowry acid and base from a given reaction.
~An acid is a proton donor
~A base is a proton acceptor
H3PO4 + H20 H3O+ +H2PO4-
H3PO4 is an acid so it is a proton donor. It gives its positive atom to the other element 2. Be able to calculate the pH of a solution given [H3O+]
Example: What is the pH of a solution with a [H3O+] of 1 x 10-2 M?
The pH level should equal the exponent number of 2.
Redox Reactions: Be able to identify what is reduced and what is oxidized in a redox reaction. Ex: What is reduced in the following reaction?
2 Bi3+ + 3 Mg 2 Bi + 3 Mg2+.
The reduced element in the following is Bi (Bismuth) because that element is broken down without its charge number.
Boyle’s Law: Be able to apply Boyle’s Law to solve for either pressure or volume
Ex: A sample of helium gas occupies 1245 mL at 705 mmHg. For a gas sample at constant temperature, determine the volume of helium at 745 mmHg.
P1V1=P2V2
If the pressure goes down, the volume goes up.
V2=P1V1/P2
P1=705 mmHg
P2=745 mmHg
V1= 1245 mL
V2= (705)(1245)/745
877725/745=1179 mL=V2
Charles’ Law: Be able to apply Charles’ Law to solve for either volume or temperature (remember to convert to Kelvin)
Example: A gas at a temperature of 95 degrees C occupies a volume of 159 mL. Assuming constant pressure, determine the volume at 15 degree C.
V1=V2
T1=T2
95°C+273=368K= T1
159 mL=V1
15°C + 273=288 T2
V2= (368)(159)/288=204 mL
Ideal Gas Law: 1. Be able to calculate molar mass given density
Example: For a gas at standard temperature and pressure with a density of 2.75 g/L. determine its molar mass.
Standard temperature and pressure occupies a volume of about 22.4 L. This is known as the standard molar volume of a gas.
V=cn (where c is a constant) n is number of molecules 2. Be able to calculate volume or pressure, using PV=nRT
P=pressure, V=Volume, n=number of moles of gas,