Chemistry Final Review Session 1 - May 5, 2011

Density • Density = Mass/Volume

Density Graph What is the density of salt water?

Precision vs accuracy • accuracy = how close a result is to the ACTUAL value • precision = how close together a set of results are to one another

Mixtures, compounds • What is the difference between a mixture and a compound?

Chemical vs physical changes • Physical change = no change in composition • Chemical change = change in chemical composition

SI system • Be able to convert between units • milli, centi, deci, deca, kilo, etc.

• meters, kilograms, liters,

Ways to separate mixtures • Physical means of separating mixtures • Distillation • Filtration • Chromatography (pass mixture through a physical medium smallest molecules travel farthest, etc.)

How to draw a graph • Descriptive Title • Scale for maximum coverage of graph area • Set Origins for maximum expression of data features • Axis Labels with Units • Points clearly indicated • Smooth curve, not dot-to-dot

Nomenclature - IOnic • MgCl 2 • NaNO 3 • Fe 2 O 3 • FeO • NaC 2 H 3 O 2

Writing compounds • You have an ionic compound of Aluminum and the polyatomic ion sulfate. What is the correct formula?

• What is the correct formula for Calcium Oxide?

• What is the correct formula for Cu(II) Hydroxide?

• H 2 O • NO • SO 2 • CSe 2 Covalent nomenclature

Moles • How many moles of Oxygen atoms in 3 moles of water?

• What is the molar mass of CO 2 ? C 6 H 12 O 6 ?

• How many atoms in 3 moles of B 2 O 3 ?

Percent composition • What is the percent composition of Carbon in CO 2 ?

Empirical formula • Butyric acid gets its name from the Latin "butyrum", meaning butter, and is the compound in rancid butter that gives it its terrible smell. A 2.50 g sample of butyric acid was found to consist of 1.36 g carbon, 0.23 g hydrogen, and 0.91 g oxygen. Find its empirical formula.

Empirical formula • Natural gas is a mixture of several hydrocarbons, but is primarily methane. Find the empirical formula of this important natural resource if its composed of 74.8% carbon and 25.2% hydrogen

Molecular formula • The simplest formula for vitamin C is C 3 H 4 O 3 . Experimental data indicates that the molecular mass of vitamin C is about 180. What is the molecular formula of vitamin C?

BAlancing equations • Balance the following equations: • ____ Na 3 PO 4 + ____ KOH ____ NaOH + ____ K 3 PO 4 • ____ Na 3 PO 4 + ____ CaCl 2 ____ NaCl + ____ Ca 3 (PO 4 ) 2 • ____ CH 4 + ____ O 2 ____ CO 2 + ____ H 2 O

Types of reactions • A + B --> AB • AB --> A + B • AB + C --> CB + A • AB + CD --> AD + CB • Hydrocarbon + O 2 --> CO 2 + H 2 O + heat