Chemistry Lab Survival Guide Flashcards

Flashcards for key chemistry lab concepts

Mass

The amount of matter in an object.

Weight

The force of gravity on an object.

Accuracy

How close a measurement is to the true value.

Precision

How reproducible a measurement is.

Beam Balance

Less precise balance, measures to 0.1g.

Analytical Balance

More precise balance, measures to 0.0001g.

Systematic Errors

Consistent, predictable errors that can be corrected.

Random Errors

Unpredictable errors that affect precision.

Beakers

Least accurate glassware, for rough estimates.

Graduated Cylinders

More accurate than beakers, for approximate volumes.

Volumetric Flasks

Highly accurate glassware, for preparing solutions of known concentration.

Burets

Highly accurate glassware, for titrations.

Density

Density = mass/volume.

Chromatography

Separating mixtures based on polarity.

Paper Chromatography

Uses a polar paper and a nonpolar solvent.

Rf Value

Rf = (distance traveled by dye) / (distance traveled by solvent).

Ionic Compounds

Metal + nonmetal.

Molecular Compounds

Nonmetals bonding together.

Binary Acids

Hydro- prefix and -ic suffix (e.g., hydrochloric acid).

Oxyacids

-ate becomes -ic, -ite becomes -ous (e.g., sulfuric acid, sulfurous acid).

Bases

Cation + hydroxide (OH-).

Hydrates

Compounds with water molecules incorporated into their structure.

Ionic Compounds

Conduct electricity when dissolved in water (electrolytes).

Covalent Compounds

Typically do not conduct electricity when dissolved in water (nonelectrolytes).

Strong Electrolytes

Bright light in conductivity tests.

Weak Electrolytes

Dim light in conductivity tests.

Nonelectrolytes

No light in conductivity tests.

Theoretical Yield

Maximum amount of product that can be formed based on the limiting reactant.

Percent Yield

(% yield) = (actual yield/theoretical yield) x 100%.

Ideal Gas Law

Pressure x Volume = moles x ideal gas constant x Temperature.

Molar Mass

mass/n (mass divided by moles).

Calorimetry

Measuring heat transfer.

Heat Transfer Principle

Heat lost = heat gained.

Heat Calculation

q = mcAT (heat = mass x specific heat capacity x change in temperature).

Titration

Acid-base neutralization.

Standardization

Determining the exact concentration of a solution using a primary standard.

Exothermic Reactions

Release heat (get hotter).

Enthalpy Change

AH = -q/moles (negative for exothermic reactions).