Chem lab final
Volume of a sphere
(4/3)(pi)(r^3)
Volume of a cylinder
(pi)(r^2)xheight
A burette was improperly read to 1 decimal place giving a reading of 21.7 mL. If the actual volume is 21.86 mL, what is the percent error caused by this mistake?
.7% error
A cube has a mass of 501.0g and a density of 5.739 g/cm^3. What is the length of a side of this cube?
4.436cm
A 20.00 mL volumetric pipet is determined to actually deliver 18.81 mL. What is the percent difference?
6% difference
Electrolyte
A chemical compound that conducts electricity by changing into ions when dissolved in a solution
Dehydration
A chemical reaction that involves the loss of water
Meniscus
A curved liquid that should be read at eye level
Anhydrate
A hydrate that lost its water molecules
Anion
A negatively charged ion
Cationand product sides in a reaction
A positively charged ion
Titration
A reaction is carried out with the controlled addition of one reactant to another until both are consumed
pH
A scale used to determine level on a scale of acidity and basic properties ?
Hydrate
A substance that contains water
Spectator ion
An ion that exists in the same form on both reactant
Which glassware is not accurate for measurement
Beaker
Which glassware can be used for approximate measurement?
Graduated cylinder
Accuracy
How close a measurement is to the actual value
In a titration, how close should the endpoint be to the equivalence point?
Ideally as close as possible, but less than 1 drop of excess NaOH beyond the equivalence point
What is a complete ionic equation
Individual elements separated with charges included. One exception is the solid that is formed
Volume by displacement
Measuring the volume of an irregularly shaped object by filling a graduated cylinder with water then adding the object and finding the amount of water displaced
Solubility
The ability of the solute to dissolve in the solvent
Briefly describe why the accuracy of the values read from a beaker is less than that from a graduated cylinder
The beakers diameter is much larger than the burette the widths of the markings on the beaker are larger than the cylinder's or burettes
Precipitate
The creation of a solid (precipitate) from a reaction
What is a molecular equation
an equation including compounds on both reactants and product sides
What is a net ionic equation
an equation that only shows what has changed from (aq) to (s)
Malleability
degree to which shaping is possible
Chemical property
displayed when a substance undergoes a chemical reaction to produce products
Secondary standard
lack at least one of the criteria to make them a primary standard. Could be expensive or low molar mess, etc.
How would you correct a bunsen burner flame when the flame appears yellow and produces soot and smoke
loosen the barrel at the base so more air is allowed in to create an ideal air/fuel mixture
Primary standard
made from compounds that have a high molar mass and are available at low cost
What two things are read to 2 decimal places
scales and pipets
Conductivity
the ability of a solution to conduct electricity, this property indicates the presence of ions
Precision
the ability to reproduce the measurement
Density
the measurement of the amount of mass in an object divided by the volume
Given a piece of glassware has markings to the tenths place X.X, to what place is a measurement recorded?
the measurement past that, so X.XX
Physical property
things such as color, state, density, and melting points
How would you correct a bunsen burner flame when the flame is burning above the barrel
tighten the needle valve to reduce flow of gas making the size of the flame smaller
Which glassware can be used for accurate measurement?
volumetric burrettes and pipets
Neutralization reaction
when an acid and a base react to form water and a salt
Endpoint of a titration
when the titration is stopped
Equivalence point of a titration
when there are no remaining reactants
