U3-5 Flashcards
What are the steps to creating an empirical formula?
Using percent composition
- Percent to mass
- Mass to moles
- Divide by small
- multiply til whole
How do you determine the molecular formula of a molecule?
- Calculate the empirical formula
- Calculate the molar mass of the empirical formula
- Divide the given molar mass by the empirical molar mass
How do you do a percent yield calculation?
Actual yield / Theoretical x 100
What is an aqueous solution?
a solution where water is the solvent
What is solubility?
the amount of solvent that dissolves in a given volume of solvent, in covalent molecules, like dissolves like
Define solute
The minor component in a solution, the solute is dissolved in the solvent
Define solvent
The larger component of a solutions, the solvent dissolves the solute
Define spectator ion
elements/compounds that are not involved in the reaction, in net ionic equations they are removed
Define Arrhenius acid
acids dissociate into H+ ions
Define Arrhenius base
bases dissociate into OH- ions
Define Bronsted/Lowry acid
acid loses hydrogen ions
Define Bronsted/Lowry base
bases gain hydrogen ions
Define pH scale
pH stands for power of hydrogen, the pH scale measures acidity and alkalinity 1 is very acidic 7 is neutral 14 is very basic
Define titration
Titration is a technique where a solution of known concentration is used to determine the concentration of an unknown solution
Define dilution
To decrease the concentration of a solute in solution, usually by mixing in more solvent
Define neutralization
A chemical reaction in which an acid and a base react quantitatively with each other, usually resulting with water and salt
Define meniscus
The curved upper surface of a liquid in a tube
Define a strong acid/base
An acid or base that ionizes completely
Define a weak acid/base
An acid or base that ionizes slightly in water (less than 50%)
List 6 strong acids`
HCl, HBr, HI, HNO3, H2, SO4
List 5 strong bases
NaOH, CsOH, LiOH, KOH, Ca(OH)2
How to make predictions about solubility?
- Ion charge - large charges on ions reduce the solubility of the ionic solute - large charges have a stronger attraction so less soluble
- Ion size - smaller ions reduce the solubility since they have stronger ionic attractions
Procedure to prepare a diluted stock solution
- Pour stock solution in a beaker
- Use a 10 mL pipette to measure out the stock solution
- Hold the pipette vertically with a 200 mL volumetric flask at an angle with the pipette the tip of the pipette should be resting on the edge of the glass
- Drain the contents from the pipette into the flask
- Add solvent to the volumetric flask with small amounts at first swirling the flask after adding the solvent each time, do this until the meniscus of the solution is resting on the etched line
What is Boyle’s law?
P1V1 = P2V2
- inverse relationship
- A larger volume means more space which means less collisions which will mean a lower pressure
What is Charles law?
V1/t1 = V2/t2
- Direct relationship
- when the temperature goes up the molecules get excited and need more space to move around
What is the Gay Lussac law?
P1/t1 = P2t2
- direct relationship
- when the temperature goes up the molecules get excited causing more particle collisions
What is Avogadro’s law?
V1/n1 = V2/n2
- direct
- when the volume goes up the number of moles goes
What is the kinetic molecular theory of ideal gases?
- Individual gas molecules have virtually no volume (no)
- There aren’t attractive or repulsive forces between molecules (no)
- The molecules have high translational energy / they move randomly in straight lines (yes)
- When the molecules collide with each other or the wall there is no loss of kinetic energy (no)
- Ave. kinetic energy of gas molecules is directly related to temp. (Yes)
