AP Chemistry Review Ch 1-4

When 78.0 g of aluminum hydroxide, Al(OH)3 (molar mass = 78.0 g/mol), reacts with 49.0 g sulfuric acid, H2SO4 (molar mass = 98.1 g/mol), what mass of water is produced? The equation is: 2Al(OH)3 (s) + 3H2SO4 (aq) Al2(SO4)3(aq) + 6H2O(l) A) 18.0 g B) 36.0 g C) 54.0 g D) 127g

A) 18.0 g

Which of the following reaction mixtures would produce the greatest amount of product, assuming all went to completion.Each involved the reaction below: N2(g) + 3H2(g) 2NH3(g) A) 2mol N2and4molH2 B) 1mol N2and5molH2 C) 4mol N2and2molH2 D) 5mol N2and1molH2

A) 2mol N2and4molH2

Bromine exists naturally as a mixture of bromine-79 and bromine-81 isotopes. An atom of bromine-79 contains A) 35 protons, 44 neutrons, 35 electrons B) 34 protons and 35 electrons, only C) 44 protons, 44 electrons, and 35 neutrons D) 35 protons, 79 neutrons, and 35 electrons

A) 35 protons, 44 neutrons, 35 electrons

Four substances with the following structures are placed on chromatography paper with water as the mobile phase. The paper is allowed to touch the water. After an hour, which substance will have moved the farthest on the paper? A) A B) B C) C D) D

A) A

A chemical reaction has the equation: 2A + B C. Which of the following figures best illustrates a stoichiometric ratio of A and B? I. II. III. IV. A) I only B) II only C) III only D) IV only

A) I only

The density of gasoline (a nonpolar liquid) is 0.7025 g/mL at 20°C. When gasoline is added to water: A) It will float on top. B) It will sink to the bottom. C) It will mix so you can't see it. D) The mixture will improve the running of the motor.

A) It will float on top.

Which of the following compounds contains the greatest percent by mass of nitrogen? A) NH3 B) HCN C) N2O D) NI3

A) NH3

Equal masses (in grams) of hydrogen gas and oxygen gas are reacted to form water. Which substance is limiting? A) Oxygen gas is limiting. B) Hydrogen gas is limiting. C) Water is limiting. D) Nothing is limiting.

A) Oxygen gas is limiting.

Which of the following pairs can be used to illustrate the law of multiple proportions? A) SO and SO2 B) CO and CaCO3 C) H2O and C12H22O11 D) H2SO4 and H2S

A) SO and SO2

The mass percent of carbon in pure glucose C6H12O6 is 40.0 percent. A chemist analyzes an impure sample of glucose and determines that the mass percent of carbon is 38.2 percent. Which of the following impurities could account for the low mass percent of carbon in the sample? A) Water, H2O B) Ribose, C5H10O5 C) Fructose, C6H12O6, an isomer of glucose D) Sucrose, C 12H22O11

A) Water, H2O

The correct name for P3- is A) phosphide ion B) phosphorus ion C) phosphorus(III) ion D) phospho(III) ion

A) phosphide ion

Which metals form cations with varying positive charges? A) transition metals B) Group 1 metals C) Group 2 metals D) Group 3 metals

A) transition metals

If 200 mL of 0.60 M MgCl2(aq) is added to 400 mL of distilled water, what is the concentration of Mg2+(aq) and Cl-(aq) in the resulting solution? (Assume volumes are additive.) [Mg2+] (mol/L) [Cl-](mol/L) A) 0.20, 0.20 B) 0.20, 0.40 C) 0.40, 0.40 D) 2.0, 2.5

B) 0.20, 0.40

Which of the following has 61 neutrons, 47 protons, and 46 electrons?A) 80/61 Pm B) 108/47 Ag+ C) 108/46 Pd- D) 108/47 Cd+

B) 108/47 Ag+

Given the equation 3A+BC+D, you react 2 moles of A with 1 mole of B. Which of the following is true? A) A is the limiting reactant because of its higher molar mass. B) A is the limiting reactant because you need 3 moles of A and have 2. C) B is the limiting reactant because you have fewer moles of B than A. D) B is the limiting reactant because 3 A molecules react with 1 B molecule.

B) A is the limiting reactant because you need 3 moles of A and have 2.

A compound is composed of element X and hydrogen. Analysis shows the compound to be 80% X by mass, with three times as many hydrogen atoms as X atoms per molecule. Which element is element X?A) He B) C C) F D) S

B) C

All of the following are true except: A) Ions are formed by adding electrons to a neutral atom. B) Ions are formed by changing the number of protons in an atom's nucleus. C) Ions are formed by removing electrons from a neutral atom. D) An ion has a positive or negative charge.

B) Ions are formed by changing the number of protons in an atom's nucleus.

A compound is analyzed and found to contain 1.30 moles of Na, 0.65 moles of Te, and 2.60 moles of O. What is the simplest formula of this comound? A) NaTeO2 B) Na2TeO4 C) Na2Te2O D) Na2Te4O

B) Na2TeO4

Equal masses (in grams) of nitrogen (gas) and oxygen (gas) are reacted to form N2O. Which substance is limiting? A) Oxygen gas is limiting. B) Nitrogen gas is limiting. C) N2O is limiting. D) Nothing is limiting.

B) Nitrogen gas is limiting.

Which of these statements is a consequence (follows from) the Law of Multiple Proportions? A) All samples of chlorine contain 35Cl and 37Cl in the same (definite) ratio. B) The mass of oxygen that is combined with a fixed mass of nitrogen in each of the binary nitrogen oxides can be expressed as a ratio of small whole numbers. C) The atomic masses of all of the elements in the periodic table have fixed values. D) The % lead by mass in the compound galena is the same for all pure samples obtained from any source. E) None of these is correct

B) The mass of oxygen that is combined with a fixed mass of nitrogen in each of the binary nitrogen oxides can be expressed as a ratio of small whole numbers.

A scientist obtains the number 0.045006700 on a calculator. If this number actually has four (4) significant figures, how should it be written?A) 0.4567B) 0.0450 C) 0.04501 D) 0.04500

C) 0.04501

Calculate the concentration of chloride ions when 200.0 mL of 1.00 M sodium chloride is mixed with 300.0 mL of 1.00 M magnesium chloride. A) 1.00 M B) 1.40 M C) 1.60 M D) 2.00 M

C) 1.60 M

The numbers of protons, neutrons, and electrons in 39/19K+ A) 20p,19n,19e B) 19p,20n,20e C) 19p,20n,18e D) 19p,20n,19e

C) 19p,20n,18e

A graduated cylinder contains multiple different liquid layers. Small samples are taken from the liquids at various heights and tested for density, viscosity, and boiling point. Given the data below, how many different liquids are present? A) 1 B) 2 C) 3 D) 4

C) 3

You have two solutions of sodium chloride. One is a 2.00 M solution, the other is a 4.00 M solution. You have much more of the 4.00 M solution and you add the solutions together. Which of the following could be the concentration of the final solution? A) 2.70 M B) 3.00 M C) 3.50 M D) 6.00 M

C) 3.50 M

How many oxygen atoms are there in 4 formula units of Al2(CO3)3? A) 9 B) 24 C) 36 D) 13

C) 36

What is the approximate molar mass of ethanol (C2H5OH)? A) 92 g/mol B) 34 g/mol C) 46 g/mol D) 30 g/mol

C) 46 g/mol

What is the coefficient for oxygen when the following equation is balanced? NH3(g) + O2(g) NO2(g) + H2O(g) A) 3 B) 6 C) 7 D) 12

C) 7

Naturally occurring copper exists in two isotopic forms: 63Cu and 65Cu. The atomic mass of copper is 63.55 amu. What is the approximate natural abundance of 63Cu?A) 30%B) 95% C) 70% D) 50%

C) 70%

_________ are substances with constant composition that can be broken down into elements by chemical processes.A) SolutionsB) Mixtures C) Compounds D) Quarks

C) Compounds

Aqueous solutions of sodium sulfide and copper(II) chloride are mixed together. Which statement is correct? A) Both NaCl and CuS precipitate from solution. B) No reaction will occur. C) CuS will precipitate from solution. D) NaCl will precipitate from solution.

C) CuS will precipitate from solution.

The elements I and Te have similar average atomic masses. A sample that was believed to be a mixture of I and Te was run through a mass spectrometer, resulting in the data below. All of the following statements are ture. Which one would be the best basis for concluding that the sample was pure Te? A) Te forms ions with a -2 charge, wereas I forms ions with a -1 charge B) Te is more abundant than I in the universe C) I consists of only one naturally occuring isotope with 74 neutrons, whereas Te has more than one isotope D) I has a higher first ionization energy than Te does

C) I consists of only one naturally occuring isotope with 74 neutrons, whereas Te has more than one isotope

As part of the calibration of a new laboratory balance, a 1.000-g mass is weighed with the following results: Trial Mass 1 1.201 0.001 2 1.202 0.001 3 1.200 0.001 The balance is: A) Both accurate and precise. B) Accurate but imprecise. C) Precise but inaccurate. D) Both inaccurate and imprecise.

C) Precise but inaccurate.

The simplest formula for a compound made from element X (molar mass = 79.0 g/mol) that is 21.0% nitrogen by mass is: A) XN B) XN2 C) X2N3 D) X3N2

C) X2N3

When a sample of an unknown element is vaporized and injected into a mass spectrometer the results shown below are obtained. Use these data to estimate the average atomic mass of this element. A) 117 amu B) between 117 and 118 amu C) between 118 and 119 amu D) between 119 and 120 amu

C) between 118 and 119 amu

The state of matter for an object that has a definite volume but not a definite shape is A) solid state B) liquid state C) gaseous state D) elemental state

C) gaseous state

The amount of uncertainty in a measured quantity is determined by: A) both the skill of the observer and the limitations of the measuring instrument B) neither the skill of the observer nor the limitations of the measuring instrument C) the limitations of the measuring instrument only D) the skill of the observer only

C) the limitations of the measuring instrument only

Ag+(aq) + Cl-(aq) AgCl(s) A student mixes dilute AgNO3(aq) with excess NaCl(aq) to form AgCl(s), as represented by the net ionic equation above. Which of the diagrams below best represents the ions that are present in significant concentrations in the solution? (Ksp for AgCl is 1.8 x 10-10).

C, (2 NO3-, 2 Cl-, 4 Na+)

Beaker X and Y each contain 1.0 L of solution, as shown above.. A student combines the solutions by pouring them into a larger, previously empty beaker Z and observes the formation of a white precipitate. Assuming that volumes are additive, which of the following sets of solutions could be represented by the diagram above? Beaker X, Beaker Y, Beaker Z A) 2.0 M AgNO3, 2.0 M MgCl2, 4.0 M Mg(NO3)2 and AgCl(s) B) 2.0 M AgNO3, 2.0 M MgCl2, 2.0 M Mg(NO3)2 and AgCl(s) C) 2.0 M AgNO3, 1.0 M MgCl2, 1.0 M Mg(NO3)2 and AgCl(s) D) 2.0 M AgNO3, 1.0 M MgCl2, 0.5 M Mg(NO3)2 and AgCl(s)

D) 2.0 M AgNO3, 1.0 M MgCl2, 0.5 M Mg(NO3)2 and AgCl(s)

A sample of chemical X is found to contain 5.0 grams of oxygen, 10.0 grams of carbon, and 20.0 grams of nitrogen. The law of definite proportion would predict that a 70 gram sample of chemical X should contain how many grams of carbon? A) 5.0 grams B) 7.0 grams C) 10. grams D) 20 grams

D) 20 grams

The empirical formula of a group of compounds is CHCl. Lindane, a powerful insecticide, is a member of this group. The molar mass of lindane is 290.8 g/mol. How many atoms of carbon does a molecule of lindane contain?A) 2B) 3C) 4D) 6

D) 6

Consider two organic molecules, ethanol and benzene. One dissolves in water and the other does not. Why? A) They have different molar masses. B) One is ionic, the other is not. C) One is an electrolyte, the other is not. D) Ethanol contains a polar O-H bond, and benzene does not.

D) Ethanol contains a polar O-H bond, and benzene does not.

In which of the following species is the oxidation state for nitrogen the greatest (highest, or most positive)? A) NO B) NO2 C) N2O D) N2O5

D) N2O5

Which of these statements is a consequence (follows from) the Law of Definite Proportion? A) All samples of chlorine contain 35Cl and 37Cl in the same (definite) ratio. B) The mass of oxygen that is combined with a fixed mass of nitrogen in each of the binary nitrogen oxides can be expressed as a ratio of small whole numbers. C) The atomic masses of all of the elements in the periodic table have fixed values. D) The % lead by mass in the compound galena is the same for all pure samples obtained from any source.

D) The % lead by mass in the compound galena is the same for all pure samples obtained from any source.

Which one of the following statements about atomic structure is false? A) An atom is mostly empty space. B) Almost all of the mass of the atom is concentrated in the nucleus. C) The protons and neutrons in the nucleus are very tightly packed. D) The number of protons and neutrons is always the same in the neutral atom.

D) The number of protons and neutrons is always the same in the neutral atom.

All of the following are characteristics of metals except: A) good conductors of heat B) malleable C) ductile D) tend to gain electrons in chemical reactions

D) tend to gain electrons in chemical reactions