Exam 2 Review

The Mole: A Measurement of Matter

100

What do you use to relate two different units?

Conversion factor

200

What is the numerical value of Avogadro's Number?

6.02 x 10^23 particles/atoms/molecules

300

What are the three ways you can measure something?

Count, Mass, Volume

400

How do you calculate Molar Mass/Molecular Weight?

Multiply each element according to the number of elements in the formula then take the sum total.

500

How many moles Mg is 2.50 x 10²³ atoms of Mg?

0.42 moles of Mg

Mole-Mass and Mole-Volume Relationships

100

Describe Avogadro's Hypothesis

Whether the particles are large or small, large expanses of space exist between individual particles of gas.

200

What is Standard Temperature and Pressure (STP)?

0⁰C and 1 atm or 101.3 kPa

300

What is the volume of a gas at STP?

22.4 L

400

Determine the volume, in liters, of 0.5 mol SO2 gas at STP conditions.

11.2 L SO2 gas

500

What is the mass, in grams, of 10.0 mol of aluminum oxide? (Molar Mass of Al2O3 is 102 g/mol)

1020 g Al2O3

Percent Composition and Chemical Formulas

100

Define percent composition.

The percent by mass of each element in the compound.

200

Define empirical formula.

The empirical formula of a compound gives the lowest whole-number ratio of the atoms or moles of the elements in a compound.

300

What is the empirical formula of Ethyne (C₂H₂) and Styrene (C₈H₈)?

CH

400

What is the % composition of Carbon in CH₄?

75%

500

What is the % composition of Hydrogen in CH₄?

25%

Types of Chemical Reactions

100

What type of reaction is: 2FeCl3(aq) + 3Zn(s) → 2Fe(s) + 3ZnCl2(aq)

Single displacement

200

What type of reaction is: P2O5(g) + 3H2O(l) → 2H3PO4(aq)

Combination or Synthesis

300

What type of reaction is: (NH4)2CO3(s) → 2NH3(g) + H2O(l) + CO2(g)

Decomposition

400

What type of reaction is: 2HNO3(aq) + Mg(OH)2(aq) → Mg(NO3)2(aq) + 2H2O(l)

Double displacement

500

Determine the product(s) from the reaction: SrCl2(aq) + 2AgNO3(aq) →

SrCl2(aq) + 2AgNO3(aq) → 2AgCl + Sr(NO3)2

Reactions in Aqueous Solution

100

When an ionic compound dissolves in water, what do the ions do?

Dissociate

200

What is a spectator ion?

An ion that appears on both sides of an equation and is not directly involved in the reaction is called a spectator ion.

300

According to the solubility rules, which ones are very insoluble?

Carbonates (-CO3), phosphates (-PO4), chromates (-CrO4), sulfides (-S), and hydroxides (-OH)

400

Using the solubility rules, is NaNO3 soluble or insoluble?

Soluble

500

Balance the equation: C3H8 + O2 ---> H2O + CO2

 C3H8 + 5O2 ---> 4H2O + 3CO2