Chem Test 1, 2, 3, & 4

Determine the percent yield of a reaction that produces 28.65 g of Fe when 50.00 g of Fe2O3 react with excess Al according to the following reaction. Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s)

81.93 %

How many kL does a 9.45 × 108 cL sample contain?

9.45 × 103 kL

How many sodium ions are contained in 99.6 mg of Na2SO3? The molar mass of Na2SO3 is 126.05 g/mol.

9.52 × 1020 sodium ions

How many C2H4 molecules are contained in 45.8 mg of C2H4? The molar mass of C2H4 is 28.05 g/mol.

9.83 × 1020 C2H4 molecules

Choose the best Lewis structure for SeO42⁻.

2 double bonds that have 4 dots, 2 single bonds with 6 dots

What is the energy of light associated with a transition from n=3 to n=8 in a hydrogen atom? Does this represent absorption or emission of a photon?

2.08 × 10-19 J, absorption

How many anions are there in 3.50 g of MgBr2?

2.29 × 1022 anions

Gas is sold for $1.399 per liter in Toronto, Canada. Your car needs 12.00 gallons. How much will your credit card be charged in Canadian dollars?

$63.54

Determine the oxidation state of Ti in Ti(SO4)2.

+4

What is the oxidation number of the sulfur atom in Li2SO4 ?

+6

Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction 2 NO(g) + O2(g) → 2 NO2(g) ΔH°rxn = ? Given:N2(g) + O2(g) → 2 NO(g) ΔH°rxn = +183 kJ 1/2 N2(g) + O2(g) → NO2(g) ΔH°rxn = +33 kJ

-117 kJ

Calculate the energy change associated with the transition from n=4 to n=1 in the hydrogen atom.

-2.04 × 10-18 J

Give the numbers for ml for an f orbital.

-3, -2, -1, 0, 1, 2, 3

Determine the energy change associated with the transition from n=3 to n=2 in the hydrogen atom.

-3.03 × 10-19 J

Use the information provided to determine ΔH°rxn for the following reaction CH4(g) + 4 Cl2(g) → CCl4(g) + 4 HCl(g) ΔH°rxn = ? ΔH°f (kJ/mol) CH4(g) -75CCl4(g) -96 HCl(g) -92

-389 kJ

Calculate the change internal energy (ΔE) for a system that is giving off 65.0 kJ of heat and is performing 855 J of work on the surroundings.

-65.9 kJ

How many cm3 are contained in 2.67 × 104 mm3?

2.67 × 101 cm3

According to the following balanced reaction, how many moles of NO are formed from 8.44 moles of NO2 if there is plenty of water present?3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

2.82 moles NO

Calculate the amount of heat (in kJ) necessary to raise the temperature of 53.8 g benzene by 50.6 K. The specific heat capacity of benzene is 1.05 J/g.°C.

2.86 kJ

How many liters of air are in a room that measures 11.0 ft x 12.0 ft and has an 8.00 ft ceiling? 1 in = 2.54 cm (exactly), 1 L = 103 cm3

2.99 × 104

How many milliliters of a stock solution of 12.1 M HNO3 would be needed to prepare 0.500 L of 0.500 M HNO3?

20.7

Calculate the molar mass of Al(C2H3O2)3.

204.13 g/mol

How many protons (p) and neutrons (n) are in an atom of 98 43 Tc?

43 p, 55 n

How many protons (p) and neutrons (n) are in an atom of 98/43Tc?

43 p, 55 n

Choose the valence orbital diagram that represents the ground state of Se2⁻.

4s and 4p full

Choose the valence orbital diagram that represents the ground state of Sr2⁺.

4s and 4p full

What is the mass (in kg) of 6.89 × 1025 molecules of CO2? The molar mass of CO2 is 44.01 g/mol.

5.04 kg

A 7.82 L gas cylinder contains 28.6 g of O2 and 79.5 g of Xe at 70 °C. What is the pressure exerted by the gas?

5.41 atm

Identify the number of electron groups around a molecule with an octahedral shape.

6

What is the frequency of light with a wavelength of 0.440 uM?

6.81 × 1014 sec-1

The molecular weight of urea ((NH2)2CO), a compound used as a nitrogen fertilizer, is ________ amu (rounded to one decimal place).

60.1

Calculate the wavelength (in nm) of a the red light emitted by a neon sign with a frequency of 5.00 × 1014 Hz.

600 nm

Calculate the wavelength (in nm) of the light emitted by a neon sign with a frequency of 4.60 × 1014 Hz.

651 nm

What mass (in g) does 7.98 moles of Kr have?

668 g

Gallium has an atomic mass of 69.723 amu. The Ga-69 (68.926 amu) is 60.111%. What is the amu of the other isotope?

70.924 amu

Give the mass percent of hydrogen in C14H19NO2.

8.21%

How many Zn atoms are contained in 922 g of Zn?

8.49 × 1024 Zn atoms

Choose the bond below that is the strongest.

C≡C

No two electrons can have the same four quantum numbers is known as the

Pauli exclusion principle.

Which of the following elements is a metalloid?

Sb

Which of the following statements about isotopes is TRUE?

Some elements have 3 or more naturally occurring isotopes.

What is the chemical formula for strontium hydride?

SrH2

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

Tc

Place the following in order of decreasing radius. Te2⁻F⁻O2⁻

Te2⁻ > O2⁻ > F⁻

Which of the following occur as the wavelength of a photon increases?

The frequency decreases.

Which of the following elements is a actinide?

U

Choose the ground state electron configuration for Zn2⁺.

[Ar]3d10

Give the ground state electron configuration for Se.

[Ar]4s23d104p4

Give the ground state electron configuration for Br⁻.

[Ar]4s23d104p6

Give the ground state electron configuration for Rb⁺.

[Ar]4s23d104p6

Give the ground state electron configuration for the ion of Ba.

[Kr]5s24d105p6

Two or more substances in variable proportions, where the composition is constant throughout are

a homogeneous mixture.

Lithium belongs to the ________ group of the periodic table.

alkali metal

The vertical height of a wave is called

amplitude

Write the name for Ba3(PO4)2.

barium phosphate

What element is defined by the following information? p+ = 20 no = 20 e- = 20

calcium

Which of the following elements has chemical properties similar to barium?

calcium

For a given atom, identify the species that has the smallest radius.

cation

The compound, Cu(NO3)2, is named

copper(II) nitrate.

Choose the pure substance from the list below.

diamond

Determine the electron geometry (eg) and molecular geometry (mg) of XeF4.

eg = octahedral, mg = square planar

Give the electron geometry (eg), molecular geometry (mg), and hybridization for H2O.

eg = tetrahedral, mg = bent, sp3

Give the electron geometry (eg), molecular geometry (mg), and hybridization for IF4+.

eg = trigonal bipyramidal, mg = seesaw, sp3d

Determine the electron geometry (eg) and molecular geometry(mg) of BCl3.

eg = trigonal planar, mg = trigonal planar

How many significant figures are there in the answer to the following problem?(8.881 × 2.100) + 0.590 = ?

four

The number of cycles that pass through a stationary point is called

frequency.

Choose the heterogeneous mixture from the list below.

lasagna

Give the name for SnO.

tin(II) oxide

Write the name for Sn(SO4)2. Remember that Sn forms several ions.

tin(IV) sulfate

Identify the shortest bond.

triple covalent bond

How many significant figures are there in the answer for the following problem? = ?

two

Molecules can be described as

two or more atoms chemically joined together.

Describe the reaction of the alkali metals with non-metals.

vigorous

What is the molar concentration of sodium ions in a 0.550 M Na3PO4 solution?

1.65 M

The hybrid orbital set used by the central atom in NH2Cl is

sp3

Give the hybridization for the Br in BrCl3.

sp3d

Which of the following elements has chemical properties similar to selenium?

sulfur

Choose the best Lewis structure for SO42⁻.

2 double bonds 4 dots, 2 single bonds with 6 dots

Give the possible values for ml for an s orbital.

0

What is the concentration of nitrate ions in a 0.125 M Ba(NO3)2 solution?

0.250 M

Choose the best Lewis structure for PO43⁻.

1 double bond with 4 dots, 3 single bonds with 6 dots

List the number of sigma bonds and pi bonds in a single bond.

1 sigma, 0 pi

List the number of sigma bonds and pi bonds in a triple bond.

1 sigma, 2 pi

A syringe contains 0.65 moles of He gas that occupy 750.0 mL. What volume (in L) of gas will the syringe hold if 0.35 moles of Ne is added?

1.2 L

The mass of a single arsenic atom is 1.244 × 10-22 g. This is the same mass as

1.244 × 10-25 kg.

How many moles of PCl5 will be produced if 0.331 moles of P4 is reacted with an excess of Cl2 using the following equation.P4(s) + 10 Cl2(g) → 4 PCl5(g)

1.324 mol

Lithium and nitrogen react in a combination reaction to produce lithium nitride:6 Li(s) + N2(g) → 2 Li3N(s)How many moles of lithium are needed to produce 0.45 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

1.4

How many xenon atoms are contained in 2.36 moles of xenon?

1.42 × 1024 xenon atoms

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li(s) + N2(g) → 2Li3N(s)In a particular experiment, 1.00-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.

1.67

The mass of a proton is 1.67 × 10-27 kg. What is the mass of a proton in milligrams?

1.67 × 10-21 mg

A sample of CO2 gas fills a container with a volume of 44.5 L. When the volume is decreased to 13.8 L at a constant temperature, the pressure inside the container is 6.25 atm. What was the pressure inside the container originally?

1.94 atm

Determine the density of CO2 gas at STP.

1.96 g/L

The bond angle in H2O is

104.5°

Calculate the atomic mass of element "X," if it has 2 naturally occurring isotopes with the following masses and natural abundances. X-107106.90509 amu51.84% X-109108.90476 amu48.46%

108.19 amu

Convert 250 °F into Celsius

121 °C

A 14.01 g sample of N2 reacts with 3.02 g of H2 to form ammonia (NH3). If ammonia is the only product, what mass of ammonia is formed?

17.03 g

What volume will 0.780 moles of Xe occupy at STP?

17.5 L

Calculate the mass percent composition of lithium in Li3PO4.

17.98 %

How many milliliters of a 9.0 M H2SO4 solution are needed to make 0.45 L of a 3.5 M solution?

180 mL

Give the complete electronic configuration for Ca2+.

1s22s22p63s23p6

How many significant figures are in the measurement, 0.0023?

2

How many subshells are there in the shell with n = 2?

2

How many valence electrons do alkali earth metals possess?

2

Calculate the atomic mass of magnesium if magnesium has 3 naturally occurring stable isotopes with the following masses and natural abundances. Mg-2423.9996 amu78.99% Mg-2524.9858 amu10.00% Mg-2625.9826 amu11.01%

24.32 amu

If a room requires 27.8 square yards of carpeting, what is the area of the floor in units of ft2? (3 ft = 1 yd)

250 ft2

What is the volume of 0.700 mol of neon gas at a pressure of 609.5 mm Hg and 117 °C?

27.9 L

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

28.12 %

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 K

How many valence electrons does an atom of Al possess?

3

How many atoms of oxygen are in 2.50 moles of SO2?

3.01 × 1024 atoms

How many phosphorus atoms are contained in 158 kg of phosphorus?

3.07 × 1027 phosphorus atoms

Calculate the energy of the orange light emitted, per photon, by a neon sign with a frequency of 4.89 × 1014 Hz.

3.24 × 10-19 J

Electromagnetic radiation with a wavelength of 575 nm appears as yellow light to the human eye. The energy of one photon of this light is ________ J.

3.46 × 10-19

According to the following reaction, what mass of PbCl2 can form from 235 mL of 0.110 M KCl solution? Assume that there is excess Pb(NO3)2.2 KCl(aq) + Pb(NO3)2(aq) → PbCl2(s) + 2 KNO3(aq)

3.59 g

Calculate the energy of the green light emitted, per photon, by a mercury lamp with a frequency of 5.49 × 1014 Hz.

3.64 × 10-19 J

How many grams of calcium chloride are needed to produce 5.00 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)

3.72 g

How many iron atoms are contained in 354 g of iron?

3.82 × 1024 Fe atoms

Calculate the molar mass of Ca3(PO4)2.

310.18 g/mol

A gas is at 35.0 °C and 3.50 L. What is the temperature at 7.00 L?

343 °C

What answer should be reported, with the correct number of significant figures, for the following calculation? (249.362 + 41) / 63.498

4.57

Electromagnetic radiation with a wavelength of 640 nm appears as orange light to the human eye. The frequency of this light is ________ s-1.

4.688 × 1014

How many oxygen atoms are there in 3.00 g of sodium dichromate, Na2Cr2O7?

4.83 × 1022 oxygen atoms

How many photons are contained in a flash of green light (525 nm) that contains 189 kJ of energy?

4.99 × 1023 photons

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:CaO(s) + H2O(l) → Ca(OH)2(s)In a particular experiment, a 5.50-g sample of CaO is reacted with excess water and 6.77 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

93.1

According to the following thermochemical equation, what mass of H2O (in g) must form in order to produce 488 kJ of energy? SiO2(s) + 4 HF(g) → SiF4(g) + 2 H2O(l) ΔH°rxn = -184 kJ

95.4 g

Which of the following compounds is insoluble in water?

AgCl

Only two electrons, with opposing spins, are allowed in each orbital is known as the

Aufbau principle.

What species is represented by the following information? p+ = 17 no = 18 e- = 18

Cl-

What is the chemical formula for barium oxide?

BaO

Which of the following elements is NOT a solid at room temperature?

Br

Determine the molecular formula for a compound that is 70.79% carbon, 8.91% hydrogen, 4.59% nitrogen, and 15.72% oxygen.

C18H27NO3

What is the empirical formula for a compound that is composed of 62.04% carbon. 27.55% oxygen, and 10.41% hydrogen?

C3H6O

Which of the compounds C3H8, MgCl2, Zn(NO3)2, OCl2 are expected to exist as molecules?

C3H8 and OCl2

The density of an unknown gas at 320 K is 3.97 g/L and exerts a pressure of 1.80 atm in a cylinder. What is the gas?

C4H10

What is the identity of element Q if the ion Q2+ contains 18 electrons?

Ca

Write the formula for calcium nitride.

Ca3N2

Which element has the highest first ionization energy?

Cl

Place the following in order of decreasing bond length. H-F H-I H-Br

H-I > H-Br > H-F

Identify the compound with covalent bonding.

H2O

Which compound has the shortest carbon-carbon bond length?

HCCH

A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 1.71 g/mL, 1.73 g/mL, 1.67 g/mL, 1.69 g/mL. If the actual value for the density of the sugar solution is 1.40 g/mL, which statement below best describes her results?

Her results are precise, but not accurate.

When two elements form two different compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of small whole numbers. Which law does this refer to?

Law of Multiple Proportions

Write the formula for the compound formed between lithium and sulfur.

Li2S

Which of the following is an ionic compound?

LiBr

Which of the following is an ionic compound?

Mg3(PO4)2

Identify the species that has the smallest radius.

N+3

Which of the following is a gas-evolution reaction?

NH4Cl(aq) + KOH(aq) → KCl(aq) + NH3(g) + H2O(l)

Which pair of compounds is soluble in water?

NH4I and Ni(NO3)2

Place the following in order of increasing metallic character. RbCsKNa

Na < K < Rb < Cs

If 2.0 mol of gas A is mixed with 1.0 mol of gas B to give a total pressure of 1.6 atm, what is the partial pressure of gas A and B?

PA = 1.06 atm and PB = 0.53 atm

Determine the empirical formula for a compound that is found to contain 10.15 mg P and 34.85 mg Cl.

PCl3

Identify the correct values for a 1s sublevel.

n = 1, l = 0, ml = 0

Choose the one set of quantum numbers that contains an error.

n = 4, l = 0, ml = -3

Identify the correct values for a 4f sublevel.

n = 4, l = 3, ml = -2

Which of the compounds, K H , NH3, C2H6, HF are ionic compounds?

only K H

Determine the number of protons, neutrons and electrons in the symbol here. 25/12X

p+ = 12n° = 13e- = 12

Give the name for PCl3.

phosphorus trichloride

Identify the charges of the protons, neutrons, and electrons.

protons +1, neutrons 0, electrons -1

Which of the following does NOT describe a nonmetal?

relatively unreactive

What are the possible orbitals for n = 3?

s, p, d

Give the name for NaHSO3.

sodium hydrogen sulfite