Chem lab final

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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


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