chemistry mid term lecture

A magnesium ion, Mg 2+ has how many electrons?

10

2.4 km is how many millimeters? 2,400 mm 2.4 x 104 mm 2.4 x 105 mm 2.4 x 106 mm 2.4 x 10 -5 mm

2.4 x 106 mm

How many valence electrons are in SBr4 ?

34

What is a quantum-mechanical orbital?

A probability distribution map that shows where the electron is likely to be found.

Which is the correct formula for copper(II) phosphate? Cu2PO4 Cu3(PO4)2 Cu2PO3 Cu(PO4)2 Cu(PO3)2

Cu3(PO4)2

Which electrons experience the greatest effective nuclear charge?

Valence electrons in Sulfur.

Give the name for KMnO4 potassium manganese tetroxide potassium manganate potassium permanganate potassium permagnesium potassium magnesate

potassium permanganate

Energy that is associated with the position or composition of an object is called

potential energy.

How many significant figures does the product of the following contain? 8.52010 x 7.9 2 3 4 5 6

2

If an electron occupies a "clover leaf-shaped" orbital, what is the value of its l quantum number?

2

The number of lone electron pairs in the N2 molecule is _____.

2

The chemical name for P3O2 is

...

Which of the following is the correct value for the ideal gas constant? 760 1 0.0821 0.821

0.0821

The density of mercury is 13.6 g/cm3. How many liters does 251 g of Hg occupy? 18.5 L 54.9 L 1.85 x 10 -2 L 5.42 x 10 -2 L 3.41 x 103 L

1.85 x 10 -2 L

How much heat must be absorbed by a 15.0 g sample of water to raise its temperature from 25.0 ∘C to 55.0 ∘C? (for water, Cs = 4.18 J/g ⋅∘C)

1.88 kJ

Hydrogen gas reacts with oxygen to form water: 2 H2 (g) + O2 (g) ⟶ 2 H2O (l) ΔH = - 483.5 kJ Determine the minimum mass of hydrogen gas required to produce 226 kJ of heat.

1.89 g

How many calories are in 528.5 joules?

126.3

Determine the molar mass of Freon -11 gas if a sample weighing 0.597 g occupies 100 cm3 at 95 degrees Celsius, and 1,000 mmHg. 0.19 g/mol 35.3 g/mol 70.9 g/mol 137 g/mol 384 g/mol

137 g/mol

How many oxygen atoms are on the right-hand side of the following chemical equation? 4 Fe CO3 (s) + O2 (g) ⟶ 2 Fe2O3 (s) + 4 CO2 (g)

14

Calculate the density of CO2(g) at 100 degrees Celsius and 10.0 atm pressure. 1.44 g/L 134 g/L 44.0 g/L 53.6 g/L 14.4 g/L

14.4 g/L

Most rulers are 12.0 inches long. Convert this to cm. 1 inch = 2.54 cm 30.5 cm 4.72 cm 305 cm 47.2 cm

30.5 cm

A pressure that will support a column of Hg to a height of 256 mm would support a column of water to what height? The density of mercury is 13.6 g/cm3. 348 cm 1.00 x 102 ft 18.8 mm 33.8 ft 76.0 cm

348 cm

How many protons and electrons are present in one Br 1- ion? 35 p, 35 e 80 p, 81 e 35 p, 34 e 35 p, 36 e 80 p, 34 e

35 p, 36 e

Sulfur and fluorine react to form sulfur hexafluoride: S (s) + 3 F2 (g) ⟶ SF6 (g) If 50.0 g S is allowed to react as completely as possible with 105.0 g F2, what mass of the excess reactant is left? 45.7 g 36.3 g 20.5 g 15.0 6

36.3 g

A block of copper of unknown mass has an initial temperature of 65.4 ∘C. The copper is immersed is a beaker containing 95.7 g of water at 22.7 ∘C. When the two substances reach thermal equilibrium, the final temperature is 24.2 ∘C. What is the mass of the copper block? Copper has a specific heat of 0.385 J/g⋅∘C and water has a specific heat of 4.18 J/g⋅∘C.

37.8 g

A piece of metal with a mass of 125 g is placed into a graduated cylinder that contains 25.00 mL of water, raising the water level to 56.00 mL. What is the density of the metal? 5.00 g/cm3 4.03 g/cm3 2.23 g/cm3 1.51 g/cm3 0.25 g/cm3

4.03 g/cm3

A gas occupies 2.22 L at 3.67 atm. What is the volume of the gas at 1.94 atm?

4.2

What is the wavelength of radiation that has a frequency of 6.912 x 1014s-1?

4.34 x 102 nm

Calculate the frequency of visible light having a wavelength of 686.2 nm.

4.37 x 1014/s

Calculate the amount of heat (in kJ) necessary to raise the temperature of 51.8 g benzene by 52.6 K. The specific heat of benzene is 1.72 J/g⋅∘C.

4.68

Calculate the number of grams of solute in 500.0 mL of 0.169 M KOH. 0.00151 g 166 g 4.74 g 151 g

4.74 g

How many molecules of N2O4 are in 76.3 g of N2O4 ? (the molar mass of N2O4 = 92.02 g/mol) 5.54 x 1025 7.26 x 1023 1.38 x 1024 4.99 x 1023

4.99 x 1023

The correct name for NH4NO3 is

Ammonium nitrate

Mining companies use this reaction to obtain iron from iron ore: Fe2O3 (s) + 3 CO (g) ⟶ 2 Fe (s) + 3 CO2 (g) The reaction of 167 g of Fe2O3 with 85.8 g of CO produces 72.3 g Fe. What is the limiting reactant? Fe2O3 CO Both reactants Neither reactant

CO

Which ion is isoelectronic with Ar?

Ca2+

Based on the solubility rules, which one of the following compounds should be insoluble in water? CaCO3 (NH4)2CO3 Na2CO3 K2CO3 KNO3

CaCO3

Which of the following elements is an "alkaline earth metal"? Sodium Iron Lithium Calcium Potassium

Calcium

The stock system name for CrO3 is

CHROMIUM(VI) OXIDE

How many electrons are in the 4p orbitals of vanadium?

0

How many electrons are there in the 3rd principal energy level (n = 3) of a phosphorus atom?

5

Which choice gives the correct oxidation numbers for all three elements in Rb2SO3 in the order that the elements are shown in the formula? -2, +6, -2 -1, +4, -3 +2, +4, -2 +1, +4, -2 +1, +6, -6

+1, +4, -2

The highest possible oxidation number of nitrogen is +8 +5 +3 +1 -3

+5

The oxidation number of Mn in KMnO4 is +8 +7 +5 -7 -8

+7

If an electron were occupying a 4p orbital, what would be its possible ml values?

-1, 0, +1

At what temperature will a fixed mass of gas with a volume of 125 L at 15 degrees Celsius and 750 mmHg occupy a volume of 101 L at a pressure of 645 mmHg? -73 degrees C 10.4 degrees C 2 degrees C 34 degrees C 200 degrees C

-73 degrees C

Determine the molarity of a solution formed by dissolving 3.00 moles of NaCl in enough water to yield 4.00 L of solution. 2.00 M 0.750 M 3.00 M 12.00 M 1.33 M

0.750 M

What is the concentration of barium ions in a 0.750 M BaCl2 solution? 0.375 M 0.160 M 0.150 M 0.750 M 2.25 M

0.750 M

What is the volume of 5.60 g of O2 at 7.78 atm of pressure and the temperature of 415 K ? 565 L 1.53 l 24.5 L 25.0 L 0.766 L

0.766 L

The maximum number of electrons in a atom that have the following set of quantum numbers is n = 4, l = + 3, ml= - 2, ms = + 1/2

1

How many moles of HCl are represented by 1.0 x 10 19 HCl molecules? 1.7 x 10 -5 mol 1.5 x 10 -3 mol 1.0 x 10 19 mol 36.5 mol 6.02 x 10 4 mol

1.7 x 10 -5 mol

Express the following answer in scientific notation: 0.0095 + (8.5 x 10-3) 0.0180 1.80 1.80 x 102 1.80 x 10-2

1.80 x 10-2

The diameter of an atom is approximately 1 x 10-8 cm. What is this diameter when expressed in nanometers? 1 x 10-19 nm 1 x 10-15 nm 1 x 101 nm 1 x 10-10 nm 1 x 10-1 nm

1 x 10-1 nm

What are the correct coefficients (left to right) when this chemical equation is balanced? ____PCl3 + ____H2O ⟶ ____H3PO3 + _____HCl 1, 3, 2, 1 1, 2, 1, 1 1, 3, 1, 3 3, 6, 1, 9

1, 3, 1, 3

Assuming ideal gas behavior, which of these gas samples has the greatest volume at STP? 1.0 g O2 1.0 g H2 1.0 g Ar

1.0 g H2

How many atoms are in 5.18 g of Phosphorus? 30.97 15 1.01 x 1023 6.02 x 1023

1.01 x 1023

What is the mass of one copper atom? 1.055 x 10 -22 g 63.55 g 1 amu 1.66 x 10 -24 g 9.476 x 10 21 g

1.055 x 10 -22 g

How many grams of nitrogen are there in 7.5 g of Ca(NO3)2 ? 0.64 g 1.3 g 0.15 g 1.15 g 2.3 g

1.3 g

What is the mass of 7.80 x 10 18carbon atoms? 1.30 x 10 -5 g 6.43 x 10 3 g 7.80 x 10 18 g 1.56 x 10 -4 g 12.01 g

1.56 x 10 -4 g

Calculate the density of Ar(g) at -11 degrees Celsius and 675 mmHg. 1.52 g/L 1.65 g/L -39.3 g/L 39.95 g/L 1254 g/L

1.65 g/L

Carbonic acid can form water and carbon dioxide upon heating. How much carbon dioxide, in grams, is formed from 24.8 g of carbonic acid? H2CO3 (aq) ⟶ H2O (g) + CO2 (g)

17.6

How much calcium is contained in 35.0 g of calcium fluoride?

17.96

A chemical system produces 155 kJ of heat and does 22 kJ of work. What is the ΔE for the surroundings? ΔE = heat + work

177 kJ

Which of the following represents the largest mass? 2.0 x 102 mg 0.0010 kg 2.0 x 102 cg 10.0 dg

2.0 x 102 cg

A mixture of Ar, H2 , and SO2 has a pressure of 7.85 atm. If the Ar has a mole fraction of 0.47 and H2 has a mole fraction of 0.23, what is the pressure of SO2 ?

2.355

How many sulfur atoms are there in 21.0 g of Al2S3 ? 8.42 x 10 22 atoms 2.53 x 10 23 atoms 2.14 x 10 23 atoms 6.02 x 10 23 atoms 6.3 x 10 26 atoms

2.53 x 10 23 atoms

A gas mixture consists of N2 , SO2 , and Ar, where the mole fraction of N2 is 0.55 and the mole fraction of Ar is 0.25. If the mixture is at STP in a 5.0 L container, how many molecules of SO2 are present? 4.5 x 1022 molecules 3.7 x 1023 molecules 2.7 x 1022 molecules 9.3 x 1024 molecules 1.1 x 1023 molecules

2.7 x 1022 molecules

Express the following in scientific notation. 0.0003568 3.568 x 10-4 3.568 x 104 .3568 x 10-3 .3568 x 103

3.568 x 10-4

The specific heat of gold is 0.129 J/g⋅∘C. What is the molar heat capacity of gold?

25.4 J/mol⋅∘C

How many electrons, protons, and neutrons does an Iron-55 atom have? 26 e, 26 p, 29 n 29 e, 29 p, 26 n 26 e, 29 p, 26 n 29 e, 26 p, 29 n 26 e, 29 p, 29 n

26 e, 26 p, 29 n

Calculate the mass percent composition of sulfur in the formula -Al2(SO4)3

28.10

Determine the final temperature of a gold nugget (mass = 376 g) that starts at 398 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128 J/g⋅∘C.

297.87

How many covalent bonds will a nitrogen atom usually form?

3

How many lone pairs of electrons are on the Br atom in BrCl2 1- ?

3

Which of the following measurements has 3 significant figures?

405 L

A 55.0 g aluminum block initially at 27.5 ∘C absorbs 725 J of heat. What is the final temperature of the aluminum? (The specific heat of aluminum is 0.903 J/g ⋅∘C)

42.1 ∘C

Give the number of "core" electrons for Cd.

46

Ammonia, NH3, can be synthesized by the reaction: 2 NO(g) + 5 H2 (g) ⟶ 2 NH3 (g) + 2 H2O (g) Starting with 86.3 g NO and 25.6 g H2 , find the theoretical yield of ammonia in grams.

49

How many significant figures are there in 1.3070 g? 6 5 4 3 2

5

Find the standard enthalpy of formation of ethylene, C2H4 (g), given the following data: C2H4 (g) + 3O2 (g) ⟶ 2CO2 (g) + 2H2O(l) ΔHf∘= -1411 kJ C(s) + O2 (g) ⟶ CO2 (g) ΔHf∘= -393.5 kJ H2 (g) + 1/2 O2 (g) ⟶ H2O(l) ΔHf∘= -285.8 kJ

52 kJ

A sample of nitrogen gas has a volume of 32.4 L at 20 degrees Celsius. The gas is heated to 220 degrees Celsius at constant pressure. What is the final volume of nitrogen? 2.94 L 19.3 L 31.4 L 54.5 L 356 L

54.5 L

H2 (g) + 1/2 O2 (g) ⟶ H2O (l) ΔHf∘= -286 kJ What is the enthalpy change for the following reaction? 2 H2O (l) ⟶ 2 H2 (g) + O2 (g) ΔHf∘= ?

572 kJ

A chromium atom has how many unpaired electrons?

6

When you balance the following equation, what is the "sum" of all of the coefficients? Co2O3 + C ⟶ Co + CO2 4 24 12 8 14

8

What element is undergoing reduction (if any) in the following reaction? Zn (s) + 2 AgNO3 (aq) ⟶ Zn(NO3)2 (aq) + 2 Ag (s) Ag N Zn O This is not an oxidation-reduction reaction

Ag

6.0 km is how many micrometers? 6.0 x 106 µm 1.7 x 10-7 µm 6.0 x 109µm 1.7 x 10-4 µm 6.0 x 103 µm

6.0 x 109µm

What volume (in mL) will a sample of F2 gas occupy at 5.5 atm, if the F2 has an initial volume of 30.0 mL at 1.2 atm?

6.545

Methanol (CH3OH) can be synthesized by the reaction: CO (g) + 2 H2 (g) ⟶ CH3OH (g) What volume ( in liters) of hydrogen gas, at a temperature of 355 K and a pressure of 738 mmHg, is needed to synthesize 35.7 g of methanol?

66.1

A glass containing 200 g of water at 20∘C was placed in a refrigerator. The water loses 11.7 kJ as it cools to a constant temperature. What is its new temperature? The specific heat of water is 4.18 J/g⋅∘C.

6∘C

Copper metal has a specific heat of 0.385 J/g ⋅ ∘C. Calculate the amount of heat required to raise the temperature of 22.8 g of Cu from 20.0∘C to 875∘C.

7.51 kJ

Suppose you run a lab activity and you actually only form 55.9 grams of product. Theoretically, you should have formed 70.5 grams. What is your percent yield?

79.29

An oxide ion, O 2-, has how many electrons?

8

How many orbitals are contained in the third principle level (n = 3) of a given atom?

9

How many O atoms are there in 51.4 g of CaSO4 ? 4 2.40 x 1024 1.13 9.09 x 1023 2.28 x 10 23

9.09 x 1023

Manganese (IV) oxide reacts with aluminum to form elemental manganese and aluminum oxide: 3 MnO2 + 4 Al ⟶ 3 Mn + 2 Al2O3 What mass of Al is required to completely react with 25.0 g of MnO2?

9.52

How many carbon atoms are there in 10. lbs. of sugar, C12H22O11 ? 9.6 x 10 25 atoms 8.0 x 10 24 atoms 159 atoms 4.21 atoms 342 atoms

9.6 x 10 25 atoms

The correct name for Ba(OH)2 is

BARIUM HYDROXIDE

Which one of the following molecules has an atom with an incomplete octet?

BF3

Which of the following elements has the greatest metallic character?

Ba

Place the following elements in order of increasing electronegativity.

Ba<Sc<C

Which molecule or compound below contains a pure covalent bond?

Br2

Which statement best summarizes the uncertainty principle?

Either the position or the velocity of an electron can be accurately known at the same instant.

The product of the reaction between hydrogen gas and bromine is H2Br2. True False

False

Theoretical yield is the amount of product actually produced by a chemical reaction. True False

False

Which one of the following elements should have the smallest ionization energy?

K

Which element has the atomic number 79?

Gold

The alkali metal elements are found in ____ of the periodic table.

Group 1A

Identify the major ions present in an aqueous HNO3 solution. HN 1+ , O 2- OH 1- , NO3 1- OH 1- , NO H 1+ , N 3- , O 2- H 1+ , NO3 1-

H 1+ , NO3 1-

Which compound has the shortest carbon-carbon bond length?

HCCH

Identify the element that is at 4d7

Ir

If you were to increase the frequency of a source of electromagnetic radiation, what would happen to the wavelength?

It would decrease.

Identify the compound with the highest percent ionic character.

KF

Which element has the following electron configuration?1s2 2s2 2p6 3s2

Mg

Identify the substance with metallic bonding.

Na

What is the limiting reactant for the following balanced reaction if 1.8 mol Na is added to 1.4 mol Br2 to form NaBr? 2 Na(s) + Br2 (g) ⟶ 2 NaBr (s) Br2 Na Neither one. Both.

Na

Identify the major ionic species present in an aqueous solution of Na2CO3 Na2 1+ , CO3 2- Na2 1+ , C 2- , O3 Na 1+ , C 4+ , O3 2- Na 1+ , C 1+ , O 2- Na 1+ , CO3 2-

Na 1+ , CO3 2-

Which of the following solids would have the highest melting point?

NaF

Based on the solubility rules, which of the following will occur when solutions of ZnSO4(aq) and MgCl2(aq) are mixed? ZnCl2 will precipitate; Mg2+ and SO42- will be spectator ion. ZnSO4 will precipitate; Mg2+ and Cl1- will be spectator ions. MgSO4 will precipitate; Zn2+ and Cl1- will be spectator ions. MgCl2 will precipitate; Zn2+ and SO42- will be spectator ions. No precipitate will form.

No precipitate will form.

A combustion reaction involves the reaction of an element or compound with which of the following? O2 N2 H2 F2

O2

Which electron is, on average, further from the nucleus?

One is a 4p orbital.

Which of the atoms listed below is the most electronegative?

P

Which one of the following compounds does not follow the octet rule?

PF5

Which is the correct formula for lead (IV) chloride? Pb4Cl PbCl2 PbCl3 PbCl4 Pb2Cl4

PbCl4

What type of chemical bond holds the atoms together within a water molecule?

Polar covalent bond

K2S is named what?

Potassium sulfide

This is what we call the solid that is formed when two solutions are mixed. Product Reactant Molecule Precipitate

Precipitate

Identify the element that has a ground state electron configuration of[Kr]5s24d5.

Tc

The element oxygen consists of three naturally occurring isotopes: Oxygen-16, Oxygen-17, and Oxygen-18. The atomic mass of Oxygen is 16.0 amu. What can be implied about the relative abundances of these isotopes? More than 50% of all O atoms are O-17. Almost all O atoms are O-18. Almost all O atoms are O-17. The isotopes all have the same abundance, i.e. 33.3%. The abundances of O-17 and O-18 are very small.

The abundances of O-17 and O-18 are very small.

Define pressure. The force applied to a gas to condense it. The force used to compress a gas. The force exerted by solids to the surrounding area. The force exerted per unit area by gas particles as they strike the surface around them. The force used to melt a solid.

The force exerted per unit area by gas particles as they strike the surface around them.

Which of the following elements has the highest first ionization energy?

Tin

A compound is termed soluble if it dissolves in water. True False

True

All aqueous solutions are made with water. True False

True

Which of the following has the highest frequency?

UV light

Which of the following is the electron configuration for the Cl 1- ion?

[Ne]3s2 3p4

An anion is defined as a charged atom or group of atoms with a net negative charge. a stable atom. a group of stable atoms. an atom or group of atoms with a net positive charge.

a charged atom or group of atoms with a net negative charge.

The vertical height of a wave is called its what?

amplitude

The distinguishing characteristic of all electrolyte solutions is that they contain molecules. conduct electricity. react with other solutions. always contain acids. conduct heat.

conduct electricity.

An endothermic reaction causes the surroundings to

decrease in temperature.

Which property or properties of an electromagnetic wave affect(s) its ability to dislodge an electron from a metal?

frequency only

Condensation refers to which conversion? solid ⟶gas solid ⟶liquid gas ⟶liquid gas ⟶solid liquid ⟶gas

gas ⟶liquid

All of the following elements are noble gases except hydrogen helium argon krypton

hydrogen

Which of the following is NOT a derived quantity? cm3 g/mL miles/hour or mph kg

kg

Which of the following is an example of a physical property? corrosiveness of sulfuric acid lead becomes a liquid when heated to 601 degrees Celsius flammability of gasoline neutralization of stomach acid with an antacid toxicity of cyanide

lead becomes a liquid when heated to 601 degrees Celsius

Which answer places the following in order of increasing frequency?

microwaves, green light, X-rays

What type of orbital is spherical in shape?

s

Which of the following elements is a metalloid? iron aluminum silicon phosphorous

silicon

Which of the following elements is NOT a transition metal? iron copper silver chromium tin

tin

Hydrogen halides form acids when combined with water. True False

true

What is the term that refers to the distance from one point on a wave to the next analogous point, such as the distance from one wave crest to another?

wavelength