Chemistry Exam Study Set

60 flashcards covering ionic naming, gas laws, stoichiometry, moles, atomic structure, balancing equations, reaction types, acids & bases, bonding, and more.

The name iron (II) indicates that a compound contains ___

Iron ions with a 2+ charge (Fe2+)

A helium balloon (1.00 atm, 4.50 L, 20C) is released. What volume at 0.600 atm and -20C? (Combined Gas Law)

6.48 L | V2 = P1V1T2 / T1P2 = (1.00x4.50x253)/(293x0.600)

Fluorine (F) forms a binary ionic compound with lithium (Li). What is the name?

Lithium fluoride

Which statement is true about Oxygen-17 and Oxygen-18?

They are the same element - isotopes: same protons (8) but different neutrons and mass

Which property is ALWAYS conserved during a chemical reaction?

Mass (Law of Conservation of Mass)

What unit is on a graduated cylinder?

mL (milliliters)

What is the atomic number of nitrogen?

7

How many moles of Cr are in 156 grams of the element? (Molar mass Cr = 52 g/mol)

3 moles | 156 / 52 = 3

The substance that undergoes a change in a chemical reaction is called:

Reactants

Which set of coefficients balances: ?C2H6 + ?O2 -> ?CO2 + ?H2O (complete combustion of ethane)

2, 7, 4, 6 | 2C2H6 + 7O2 -> 4CO2 + 6H2O

What are the products of a neutralization reaction?

Salt and water

The type of bond formed when two atoms SHARE a pair of electrons is called a/an ___ bond?

Covalent bond

Which is a balanced equation for the synthesis of water from H2 gas and O2 gas?

2 H2 + O2 -> 2 H2O

What is the maximum possible amount of product obtained in a chemical reaction?

Theoretical yield

If percent yield = 100%, then ___

The actual yield equals the theoretical yield

How many grams of NaCl are needed to make 200 mL of a 0.5 M solution?

5.84 g | moles = 0.5 x 0.200 = 0.1 mol -> 0.1 x 58.44 = 5.84 g

In the compound CaCl2, the subscript 2 indicates that:

There are two chloride ions for each calcium ion

What piece of lab equipment is best for accurately measuring the volume of a liquid?

Graduated cylinder

2Al(s) + 3Br2(l) -> 2AlBr3(s). Which of these is NOT a mole ratio of the equation?

2 mol Al : 1 mol Br2 (correct ratio is 2 Al : 3 Br2)

Which list of elements contains ONLY metals?

Iron, copper, sodium (NOT helium, iodine, carbon, or argon)

Which of the following is NOT a common property of bases?

Reacts with metals (that is a property of ACIDS, not bases)

What is -10 degrees Celsius in Kelvin?

263 K | K = -10 + 273 = 263

How many neutrons does phosphorus have?

16 | Mass number 31 - Atomic number 15 = 16

How much of a 30 gram sample will remain after 5 half-lives?

0.9375 g | 30 x (1/2)^5 = 30/32 = 0.9375 g

Calculate the percent error: theoretical yield = 50.0 g, actual yield = 42.0 g

16.0% | |50 - 42| / 50 x 100 = 16%

What is the mass of one mole of lead tetraethyl, Pb(C2H5)4?

323 g/mol | Pb(207.2) + 4xC2H5(29) = 207.2 + 116 = 323 g/mol

Aluminum has how many protons?

13 (atomic number of Al = 13)

Volume and temperature are indirectly related. True or False?

FALSE - they are DIRECTLY related (Charles's Law: V proportional to T at constant pressure)

How many moles of gas occupy 98 L at 2.8 atm and 292 K? (R = 0.0821) (Ideal Gas Law)

11.45 mol | n = PV/RT = (2.8x98)/(0.0821x292) = 11.45

What is the compound name for CaCl2?

Calcium chloride

How much 0.100 M HCl is required to neutralize 25 mL of 0.100 M NaOH?

25 mL | moles NaOH = 0.0025 mol -> V(HCl) = 0.0025/0.100 = 25 mL

What is Avogadro's number?

6.022 x 10^23 — the number of particles (atoms, molecules, ions) in one mole of any substance

What is the molar mass of water (H2O)?

18.02 g/mol | H: 2x1.008 = 2.016, O: 16.00, Total = 18.02

What type of reaction is: A + B -> AB?

Synthesis (combination) reaction — two or more substances combine to form a single product

What type of reaction is: AB -> A + B?

Decomposition reaction — one compound breaks down into two or more simpler substances

What type of reaction is: AB + C -> AC + B?

Single replacement (substitution) reaction — one element replaces another in a compound

What type of reaction is: AB + CD -> AD + CB?

Double replacement (metathesis) reaction — the cations and anions of two ionic compounds swap partners

What is the limiting reactant in a chemical reaction?

The reactant completely used up first that determines the maximum amount of product that can form

What is Boyle's Law?

At constant temperature: P1V1 = P2V2 — pressure and volume are inversely proportional

What is Charles's Law?

At constant pressure: V1/T1 = V2/T2 — volume is directly proportional to temperature (in Kelvin)

What is Gay-Lussac's Law?

At constant volume: P1/T1 = P2/T2 — pressure is directly proportional to temperature (in Kelvin)

What volume does 1 mole of any gas occupy at STP?

22.4 L

What is STP in chemistry?

Standard Temperature and Pressure: 0°C (273 K) and 1 atm

What is the pH of a neutral solution?

7

A solution with a pH less than 7 is:

Acidic (higher H+ concentration than OH-)

A solution with a pH greater than 7 is:

Basic or alkaline (higher OH- concentration than H+)

What is the formula for percent yield?

Percent yield = (Actual yield / Theoretical yield) x 100%

What is molarity (M)?

Moles of solute per liter of solution: M = mol / L

What is an exothermic reaction?

A reaction that releases heat/energy to the surroundings — products have LESS energy than reactants

What is an endothermic reaction?

A reaction that absorbs heat/energy from the surroundings — products have MORE energy than reactants

What is oxidation in terms of electrons?

Loss of electrons — LEO: Loses Electrons = Oxidation (opposite of reduction)

What is reduction in terms of electrons?

Gain of electrons — GER: Gains Electrons = Reduction (opposite of oxidation)

What is the molar mass of NaCl (table salt)?

58.44 g/mol | Na: 22.99 + Cl: 35.45 = 58.44

How many electrons does a neutral sodium (Na) atom have?

11 electrons (equal to its atomic number)

What is an ionic bond?

A chemical bond formed by the TRANSFER of electrons from a metal to a nonmetal, creating oppositely charged ions that attract each other

What is a catalyst?

A substance that speeds up a chemical reaction without being consumed or permanently changed itself

What is the charge of a sulfate ion (SO4)?

2- (written as SO4^2-)

Balance the equation: Fe + O2 -> Fe2O3. What are the coefficients?

4, 3, 2 | 4Fe + 3O2 -> 2Fe2O3 (check: Fe 4=4, O 6=6)

Balance: N2 + H2 -> NH3. What are the coefficients?

1, 3, 2 | N2 + 3H2 -> 2NH3 (check: N 2=2, H 6=6) — this is the Haber process for making ammonia

What is the molar mass of CO2?

44.01 g/mol | C: 12.011 + O: 2x16.00 = 44.01