CHM 113 Final Study

If a system absorbs 155.0 kJ of heat from its surroundings and the system does 55.0 kJ of work on its surroundings, what is the change in the internal energy of the system, in kJ?

-210 kJ

For the chemical reaction H₂ (g) + F₂ (g) → 2 HF (g) ∆H° = -79.2 kJ/mol. What is the molar enthalpy (in kJ/mol) for the reaction 3 H₂ (g) + 3 F₂ (g) → 6 HF (g)

-237.6 kJ/mol

0.700 moles of an unknown solid is placed into water to make 150.0 mL of solution. The solution's temperature decreases by 9.81°C. Calculate ∆H, in kJ/mol, for the dissolution of the unknown solid. (The specific heat of the solution is 4.184 J/g･°C and the density of the solution is 1.02 g/mL).

-8.97 kJ/mol

Using the equations N₂ (g) + O₂ (g) → 2 NO (g) ∆H° = 180.6 kJ/mol N₂ (g) + 3 H₂ (g) → 2 NH₃ (g) ∆H° = -91.8 kJ/mol 2 H₂ (g) + O₂ (g) → 2 H₂O (g) ∆H° = -483.7 kJ/mol Determine the molar enthalpy (in kJ/mol) for the reaction 4 NH₃ (g) + 5 O₂ (g) → 4 NO (g) + 6 H₂O (g).

-906.3 kJ/mol

The answer to the calculation below with the correct number of significant figures is 0.0180-0.0059/0.03168

0.382

Convert 15.4 inches to meters. (2.54 cm = 1 inch)

0.391 m

How many moles of HNO₃ will be produced from the reaction of 38.0 g of NO₂ with excess water in the following chemical reaction? 3 NO₂(g) + H₂O (l) → 2 HNO₃(g) + NO(g)

0.55 mol

A chemist encounters an unknown metal. They drop the metal into a graduated cylinder containing water, and find the volume change is 4.1 mL. If the metal weighs 5.1 g, what is the density of the metal in g/mL?

1.2 g/mL

If 100.0 molecules of H₂ and 45.0 molecules of O₂ react, how many molecules of H₂O can be produced in the reaction below? 2 H₂(g) + O₂(g) → 2 H₂O(g)

1.49 x 10^-22 molecules

What is the bond order between the carbons in benzene (C₆H₆)?

1.5

What is the energy, in J, of light that must be absorbed by a hydrogen atom to transition an electron from n = 3 to n = 5? Submit an answer to three signficant figures.

1.55 × 10⁻¹⁹ J

The bond dissociation energy to break 3 C-H bond(s) in 1 mole of hexane (CH₃CH₂CH₂CH₂CH₂CH₃) molecules is

1233 kJ

Determine the formula weight of SrCl₂. Provide an answer to two decimal places.

158.52 amu

How many hydrogen atoms are in 29 molecules of diborane, B₂H₆?

174

Write the complete ground-state electron configuration of Ca.

1s2 2s2 2p6 3s2 3p6 4s2

Balance the following chemical equation (if necessary): H2SO4 (aq) + Pb(OH)4 (s) -> Pb(SO4)2 (s) + H2O (l)

2 H2SO4 (aq) + Pb(OH)4 (s) -> Pb(SO4)2 (s) + 4 H2O (l)

An unknown element X has the following isotopes: ²⁵X (80.50% abundant, mass = 25.03 amu) and ²⁷X (19.50% abundant, mass = 26.98 amu). What is the average atomic mass of X in amu?

25.40 amu

What is the mass percentage of Na in NaNO₃? Provide an answer to two decimal places.

27.04%

The oxidation number of a nitrogen atom in N₂O₃ is

3

In the reaction below, 7.0 mol of NO and 5.0 mol of O₂ are reacted together. The reaction generates 2.1 mol of NO₂. What is the percent yield for the reaction? 2 NO (g) + O₂ (g) → 2 NO₂ (g)

30%

What is the wavelength (in nm) of blue light that has a frequency of 6.53 × 10¹⁴ s⁻¹? (c = 3.00 × 10⁸ m/s)

4.94 × 10⁻¹⁹ J

What is the wavelength (in nm) of blue light that has a frequency of 6.53 × 10¹⁴ s⁻¹? (c = 3.00 × 10⁸ m/s)

459 nm

What is the mass number for an atom of zinc containing 30 protons and 36 neutrons?

66

What quantity in moles of H₂ are required to give off -2101 kJ of heat in the following reaction? N₂ (g) + 3 H₂ (g) → 2 NH₃ (g) ∆H° = -91.8 kJ/mol

68.69 mol

The following picture would be best described as

A gaseous compound

Which of the following temperatures is the coldest? A) 100 K B) 100 °C C) 100 °F

A) 100 K

In the reaction between HNO₃ and Ba(OH)₂ (assume complete reaction of the Ba(OH)₂), the spectator ions are A) Ba²⁺ and NO₃⁻ B) H⁺ and NO₃⁻ C) H⁺ and OH⁻ D) Ba²⁺ and OH⁻

A) Ba²⁺ and NO₃⁻

Which element is classified as a halogen? A) Cl B) O C) S D) Ar

A) Cl

Combustion of an unknown compound containing only carbon and hydrogen produces 12.3 g of CO₂ and 3.8 g of H₂O. What is the empirical formula of the compound? A) C₂H₃ B) C₃H₂ C) C₁₀H₃ D) C₄H₃

A) C₂H₃

An exothermic reaction causes the surroundings to A) warm up B) become acidic C) condense D) decrease in temperature E) release CO₂

A) warm up

Which of the following represents the electron configuration of S⁻? A) 1s²2s²2p⁶3s²3p⁶ B) 1s²2s²2p⁶3s²3p⁵ C) 1s²2s²2p⁶3s²3p⁴ D) 1s²2s²2p⁶3s²3p³ E) 1s²2s²2p⁶3s²3p²

B) 1s²2s²2p⁶3s²3p⁵

Which of the following does NOT describe the element bromine (Br)? A) A metalloid B) A nonmetal C) A main group element D) A halogen

B) A nonmetal

If light has a lot of energy, it will have: A) A small frequency B) A small wavelength C) Low speed D) High speed E) A small number of photons

B) A small wavelength

For which one of the following is the enthalpy of the reaction the same as the enthalpy of formation? A) H₂ (g) + F₂ (g) → 2 HF (g) B) Ca (s) + ½ O₂ (g) → CaO (s) C) 2 CH₃OH (l) + 3 O₂ (g) → 2 CO₂ (g) + 4 H₂O(g) D) SrO (s) + CO₂ (g) → SrCO₃ (s)

B) Ca (s) + ½ O₂ (g) → CaO (s)

Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²? A) Si B) Ge C) Sn D) Ga E) As

B) Ge

Which of the following electron configurations is incorrect? A) Ca [Ar]4s² B) Mn [Ar]4s²4d⁵ C) Cu [Ar]4s¹3d¹⁰ D) Ga [Ar]4s²3d¹⁰4p¹ E) Br [Ar]4s²3d¹⁰4p⁵

B) Mn [Ar]4s²4d⁵

In which one of the following molecules does sulfur have the smallest oxidation number? A) SO₃ B) S₂O₃²⁻ C) SO₄²⁻ D) SO₂

B) S₂O₃²⁻

A lattice dissociation enthalpy (lattice energy) is A) the energy required to break a chemical bond. B) the amount of energy that must be supplied to break an ionic solid into its individual gaseous ions. C) the difference in ionization energy and electron affinity of the anion and cation. D) the energy required to convert a substance from a solid to a gaseous state.

B) the amount of energy that must be supplied to break an ionic solid into its individual gaseous ions.

Draw the Lewis structure of Br₃⁻ and then determine its electron domain and molecular geometries. Click to edit molecule A) trigonal planar / square planar B) trigonal bipyramidal / linear C) trigonal bipyramidal / planar D) trigonal planar / trigonal E) trigonal / pentagonal

B) trigonal bipyramidal / linear

The Lewis structure of ozone (O₃) is shown on the left below with numbers on the corresponding atoms. Choose the correct set of formal charges of the atoms in ascending order of atom number. A) #1 = 0, #2 = 0, #3 = 0 B) #1 = -1, #2 = 0, #3 = +1 C) #1 = 0, #2 = +1, #3 = -1 D) #1 = +1, #2 = -1, #3 = 0 E) #1 = -2, #2 = +1, #3 = +1

C) #1 = 0, #2 = +1, #3 = -1

Which of the orbital electron configurations is not possible? A) 2s¹ B) 3d¹⁰ C) 4p⁷ D) 4f⁷ E) 2p⁶

C) 4p⁷

The first five ionization energies of an element are as follows (in kJ/mol): 577.9, 1820, 2750, 11600, 14800. Which of the following elements is most likely to have these ionization energy values? A) Na B) Mg C) Al D) Si E) P

C) Al

Which of the following is an example of an empirical formula? A) C2O2H2 B) C4H8 C) C7H14Cl2 D) C6H9O3 E) C8H10

C) C7H14Cl2

What property of water makes it a good medium for heat exchange in calorimetry? A) High liquid density B) High dielectric constant C) High specific heat capacity D) High refractive index E) High cryoscopic constant

C) High specific heat capacity

In the following chemical reaction, which element is the oxidizing agent? CH₄(g) + 2 O₂(g) → CO₂(g) + 2H₂O(g) A) C B) H C) O D) There is no oxidizing agent in this reaction.

C) O

Classify the type of reaction is represented by the following equation: BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2 NaCl(aq) A) synthesis B) decomposition C) double displacement D) single displacement

C) double displacement

Predict the chemical formula for the ionic compound formed by Cu²⁺ and P³⁻

Cu3P2

A compound containing Na, C, and O is found to have 1.06 mol Na, 0.528 mol C, and 1.59 mol O. What is the empirical formula of the compound? A) NaCO B) Na₂CO C) Na₂CO₂ D) Na₂CO₃

D) Na₂CO₃

Which of the following series of isoelectronic ions (Mg²⁺, N³⁻, F⁻, Si⁴⁺) has the ionic radii in order of largest to smallest? A) Mg²⁺ > N³⁻ > F⁻ > Si⁴⁺ B) Mg²⁺ > Si⁴⁺ > F⁻ > N³⁻ C) N³⁻ > F⁻ > Si⁴⁺ > Mg²⁺ D) N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺ E) F⁻ > N³⁻ > Si⁴⁺ > Mg²⁺

D) N³⁻ > F⁻ > Mg²⁺ > Si⁴⁺

Which following ions share an electron configuration with a noble gas? A) N⁻ B) Na²⁺ C) H⁺ D) O²⁻ E) F³⁺

D) O²⁻

Which electron configuration violates Hund's rule? A) [He]2s²2px²2py²2pz¹ B) [He]2s²2px²2py¹2pz² C) [He]2s²2px¹2py²2pz² D) [He]2s²2px²2py² E) [He]2s²2px¹2py¹2pz²

D) [He]2s²2px²2py²

The best reason for why a covalent bond forms is A) two atoms exist as ions and the ions are attracted to each other. B) the atoms that form cations have low ionization energy and anions have high electron affinity, so the two atoms exchange electrons. C) nonmetal atoms cannot react with each other unless they share electrons. D) atoms with high electronegativities will not lose electrons, so instead they share electrons to reach a stable number of valence electrons.

D) atoms with high electronegativities will not lose electrons, so instead they share electrons to reach a stable number of valence electrons.

Determine the number of atoms of O in 10.0 g of C₂H₄O₂.

Determine the number of atoms of O in 10.0 g of C₂H₄O₂.

Which of the following forms of radiation has the highest frequency? A) red light B) microwaves C) ultraviolet rays D) radio waves E) gamma rays

E) gamma rays

Which of the following is the correct Lewis symbol for a neutral atom of F?

F.......

Write the chemical formula for sulfuric acid

H2SO4

Balance the following chemical equation (if necessary): MnO2 (s) + HCl (aq) -> MnCl2 (aq) + H2O (l) + Cl2 (g)

MnO2 (s) + 4 HCl (aq) -> MnCl2 (aq) + 2 H2O (l) + Cl2 (g)

Draw the Lewis structure of carbon monoxide (CO) and then determine if the molecule is polar or nonpolar. Please place the elements in the order that they are written.

Polar

Which of the following is a physical change?

Tearing a piece of paper

Write the condensed (noble-gas) electron configuration of aluminum.

[Ne]3s13p1

Draw the Lewis structure of SCl₂ and then determine the hybridization of the central atom.

sp3