chem1a unit 1 review: chapters 1, 2, 3, 4 study...

C h e m i s t r y 1 A U n i t 1 P a g e | 1

Chem1A Unit 1 Review: CHAPTERS 1, 2, 3, 4 STUDY GUIDE FOR UNIT 1: Try numerous problems in the book to practice and work out. Review Key terms, concepts and equations. Bonus problems are due at the start of the test. For practice try the following problems as if part of a test. Do what you can at a fairly quick pace before you look in the book for help. Doing the problems is important. DO NOT just look at problems. It is important to actually pick up the pencil and calculator and WORK the problems. You must SHOW WORK on the test for full credit. This review is longer than a test. My tests generally are 7 to 9 pages with room to show problem solving work. 1. Significant Figures: A. Counting Significant Figures: Circle the significant figures

a) 5280 feet exactly c) 500 g +/- 100 g b) 0.00005640 cm d) 30.0 ml

B. Round the following to three significant figures:

a) 1.783 c) 23.3790

b) 0.005497 d) 8.2145 x 109

2. Calculations: Multiply then Round. Divide then Round

a) (9.87 )(1.23456 x 103) = b) ( . . )

. =

Add and Round

c) 744.09 g d) 321 g 9.126 g 5.971 g +32.0942 g +1.1 g Subtract and Round e) 88.9870 g f) 432.1 g -7.29 g -92.234 g


3. Conversions: a. ? m = 0.347cm b. ? °F = ? K = 345°C c. ? ml = 0.0253 L d. ? ft = 50.3 cm e. ? kg = 165 pounds f. ? m/s = 72.0 mi/hr

g. How many inches are in 2.5 km?

h. What is the value of 3.82 x 105 liter/day if you convert to units of cubic feet per minute (ft3/min)?

i. A square piece of aluminum is 10.0 cm on each side and has a mass of 7.40 grams. Given that the density of aluminum is 2.70 g/cm3, what is the thickness (mm) of the foil?


4. Match the words with the descriptions Compound a) uniform composition throughout the mixture Molecule b) the capacity to do work Atom c) a simple method of separating a solid from liquid Homogeneous d) a bonded collection of two or more atoms that may have the same or different elements Cation e) a method of separation that uses vaporization of one or more of the components Heterogeneous f) A negatively charged atom or group of atoms Mixture g) A positively charged atom or group of atoms Distillation h) a mixture with different properties in various regions Anion i) contains two or more different elements in a particular set ratio Filtration j) the fundamental unit which elements are composed Energy k) has variable composition and contains 2 or more substances Diatomic molecule l) a tentative explanation concerning some phenomenon Strong electrolyte m) gives off energy (usually heat) during a reaction Exothermic n) a brief statement, sometimes in mathematical terms, used to

summarize and describe patterns in large collections of scientific data.

Base o) a substance that breaks apart completely into ions when dissolved in water (can be an acid, base or salt)

Hypothesis p) an ionic compound which is not an acid or base Scientific law q) a substance which accepts protons Density r) refers to the closeness of the average value of a set of data

agree to the "correct" or most probable value Precision s) refers to how closely measurements of a set of data agree

with each other, reflecting the degree of reproducibility of measurements.

Acid t) molecules composed of two atoms of the same element Accuracy u) all the digits of a measurable quantity known with certainty

plus the first uncertain digit Significant figures v) the mass of a substance divided by its volume Salt w) will donate H+ions Endothermic x) takes energy to complete reaction


5. Calculate the density of the liquid Volume of liquid sample 30.2 ml,

Mass of empty container 75.843 g, Mass of container and liquid 155.633 g

6. What are the steps used when solving a problem by the scientific method? Refer to the textbook and notes

7. For the following give the name or symbol for the element, identify if each is a metal or nonmetal.

Antimony S

Copper F

Mercury Pb

8. On the periodic table, a group or family are elements in a (vertical , horizontal) row. 9. Identify which group each element belongs in… (alkali metal, alkaline earth metal,

transition metal, inner transition metal, halogen, noble gas) helium chlorine

silver calcium

potassium uranium

10. Place a P before a physical property or change and a C before a chemical property or

change:

ice melts at 0°C burning wood

silver tarnishes wax melts


11. Place a I before a intensive property and a E before an extensive property:

Density Temperature

Mass Color

12. What are the main ideas, evidence and picture of the Atomic Theories listed. a) Dalton’s Refer to the textbook and notes

b) Thomson’s Refer to the textbook and notes

c) Rutherford’s Refer to the textbook and notes

13. How did Dalton’s atomic theory explain the Law of Conservation of Mass? the Law of Definite Proportions? The Law of Multiple Proportions?

Refer to the textbook and notes 14. Fill in the blanks;

isotope atomic number

Z

mass number

A

number of protons

p

number of electrons

e-

number of neutrons

n

47107Ag

20 20 18

15. The atomic weight of chlorine is 35.453 amu. There are only two naturally occurring

isotopes: 35Cl (34.96885 amu) and 37Cl (36.9658 amu). Calculate the percent abundance of each isotope.


16. Use the principle of electrical neutrality to predict the formula of the binary compounds. a) Mg

+2 and Cl

-1 b) Fe+3

and O-2

c) Ba+2

and S-2

d) K+ and P

-3

17. Determine the oxidation number (charge) of the indicated species: Mn = in MnO2 Cu = in CuSO4 Cr = in Cr2(CO3)3 18. Write the name for the following: Write the formula for the following:

Zn3(PO4)2 tin (IV) chromate

PbSO3 hydrobromic acid

NH4CN aluminum sulfide

Cu(C2H3O2)2 nitrous acid

H2CO3 acetic acid

HNO3 sodium hydrogen carbonate

Na3PO4 . 10 H2O sodium bicarbonate

K2HPO4 sulfur

CH4 bromine

P4O10 sodium hydroxide

H2S (g) and H2S (aq) sulfur trioxide

C3H8 Lithium perchlorate trihydrate

N2O3 sulfuric acid

HClO (aq) ethane

Al2(SO3)3 iron (III) cyanide

K2C2O4 dichlorine heptoxide

CH3OH magnesium permanganate


19. Solve for the molecular weight and percent composition for (NH4)2SO4

20. For a sample of 2.045 grams of Mg(NO3)2 a) solve for the molecular weight

b) solve for the number of moles of magnesium nitrate

c) solve for the number of formula units of magnesium nitrate

d) solve for the number of oxygen atoms in the given sample of magnesium nitrate. 21. Solve for the empirical formula and molecular formula of a compound that is 24.78 % C,

2.08 % H, 73.14% Cl and has a molecular weight around 95 g/mol.

132.1 g/mol. 21.2%N, 6.1%H, 24.3%S, 48.4% O 148.3g/mol 0.01379 mol

8.304 x 10^21 formulas

4.982 x 10^22 O atoms

CHCl empirical formula


22. Sorbic acid is added to food as a mold inhibitor. Its composition is 64.3% C, 7.2% H, and 28.5% O, and its molecular weight is 112 g/mol. Solve for both the empirical formula and molecular formula.

23. Glyceraldehyde is made up of only carbon, hydrogen, and oxygen. A 30.50 mg sample

of glyceraldehyde was placed into a combustion train with extra oxygen flowing and yielded 18.30 mg H2O and 44.73 mg CO2. Its molecular weight is 90.0 g/mol. Solve for its mass percent composition, its empirical formula, and its molecular formula.


24. 4.55 mg of CH4 and 8.00 mg of oxygen react to form carbon dioxide and water. Write a balanced equation. Determine the limiting reactant and excess reactant, and the grams of everything present after the reaction goes to theoretical completion.

25. Balance N2 + H2 Æ NH3 How many grams of NH3 are prepared from 12.0 g of N2?

What is the % yield if the actual yield is 11.3 g?


26. a) Balance the equation:

Mg (s) + HCl (aq) Æ MgCl2 (aq) + H2 (g)

b) How many grams of hydrogen gas can theoretically be produced from 0.650 g of solid magnesium and 15.0 ml of 2.00 M HCl? Identify limiting reactant.

c) If 25.0 mg of hydrogen gas were experimentally produced from part b, what is the percent yield?

27. What volume of 0.500 M BaCl2 is required for complete reaction with 4.32g of Na2SO4?

Na2SO4 (aq) + BaCl2 (aq) Æ BaSO4(s) + 2NaCl (aq)

28. How should you safely prepare a 2.00 liter solution of 1.00 M HCl from a stock solution

of 12.0 M HCl, water, and a 2 L volumetric flask?

0.026 mol Mg0.0300 mol HClLimiting reactant is HCl0.0302 g Hydrogen gas theoretical yield

82.7% yield

Molarity = moles/literMW 142.0 g/mol0.0304 mol sodium sulfate= 0.0304 mol barium chloride0.0304 mol/0.500M = 0.0608 L or 60.8 ml

V of stock = (1.00M x 2.00 L)/(12.0M) = 0.167 LWear protective gear, goggles.Add about 1 to 1.5 L of water to the 2 L volumetric flaskThen add 0.167 L of 12.0 M HCl to flaskAdd more water to make a total of 2.00 L solution and mix well


29. A metal M, was converted to the metal chloride, MCl2. Then a solution of the chloride was treated with silver nitrate to give silver chloride crystals, which were filtered and dried.

MCl2 (aq) + 2 AgNO3 (aq) Æ M(NO3)2 (aq) + 2 AgCl (s) If 2.434 g of the metal M gave 7.964 g of silver chloride, what is the atomic weight of the

metal? What is the metal.

30. What are the Solubility Rules?

Refer to the textbook and notes 31. What does it mean to be a strong electrolyte? Which types of substances will be strong

electrolytes? What are the strong acids? The strong bases? Refer to the textbook and notes

32. For the double displacement reaction of aqueous nickel (II) nitrate and aqueous potassium hydroxide. Write the whole, complete ionic, and net ionic equations. Identify spectator ions, the type of double displacement reaction and driving force for the reaction. If no reaction is expected write NR

33. Write the balanced whole, total ionic and net equations for the reaction, if it occurs, for

HNO3 (aq) and Zn (s). Zn has a greater activity than H.

AgCl = 7.964 g0.0556 mol AgCl = 0.0556 mol chloride0.0278 mol M87.6 g/mol of M; M is Sr


34. Balance the following equations and Classify each chemical reaction with as many reaction types that apply. ( P precipitation, DD double replacement, N acid-base or neutralization, R redox (oxidation-reduction), S synthesis, D decomposition, C combustion, SR single replacement, G gas evolution) Identify the driving force for the reactions. a) C3H8 (g) + O2 (g) Æ CO2 (g) + H2O (g)

b) solid magnesium carbonate when heated produces gaseous carbon dioxide

and solid magnesium oxide

c) ammonia plus oxygen will produce nitrogen monoxide plus water vapor.

All the reactants and products are in the gas state.

g) Ni(s) + HNO3 (aq) Æ Ni(NO3)2 (aq) + H2 (g)

h) C5H12O (s) + O2 (g) Æ CO2 (g) + H2O (l)

i) Aqueous sodium carbonate and aqueous chloric acid react together to produce

aqueous sodium chlorate and carbon dioxide gas and water.

j) (NH4)2SO4 (aq) + Sr(OH)2 (aq) Æ SrSO4 (aq) + H2O (l) + NH3(g)


35. Predict the products and balance the reactions, include terms (s), (l), (g), & (aq):

Use NR for no reaction. a) Double displacement reaction:

KNO3 (aq) + (NH4)3PO4 (aq) Æ

b) Double displacement reaction:

aqueous acetic acid + aqueous potassium hydroxide Æ

c) Decomposition:

CaClO3 (s) Æ

d) Combination:

Mg(s) + Br2 (g) Æ

e) Acid-Base:

HCl (aq) + K2SO3 (aq) Æ

f) Double displacement or precipitation

NaCl(aq) + AgNO3(aq) Æ

g) Single replacement a type of redox

aluminum (s) + iron(III) oxide (s) Æ

h) Combustion a type of redox

Liquid butane, C4H10, reacts with atmospheric oxygen

i) Decomposition a type of redox

HgO(s) Æ

j) Double displacement or acid base reaction

Aqueous nitric acid is added to aqueous sodium bicarbonate


36. Determine the oxidation number of the indicated species: C = in C2O4-2 N = in (NH4)2S Cr = in Na2CrO4

37. a) Balance the following oxidation-reduction equation: In acidic solution: PbO2 (s) + Mn+2 (aq) Æ Pb+2 (aq) + MnO4-1 (aq) Identify what is oxidized, reduced, the oxidizing agent, and the reducing agent b) Balance in basic solution: I-1 (aq) + NO2-1 (aq) Æ NO (g) + I2 (s)

chem1a unit 1 review: chapters 1, 2, 3, 4 study...

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