Chem exam final

When filling degenerate orbitals, electrons fill them singly first, with parallel spins. This way of filling orbitals known as

Hund's rule.

Write a balanced equation to show the reaction of gaseous ethane with gaseous oxygen to form carbon monoxide gas and water vapor.

2 C2H6(g) + 5 O2(g) → 4 CO(g) + 6 H2O(g)

How many mL of a 0.155 M KCl solution contain 2.55 g KCl? (Choose the closest numerical value.)

221 mL

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

4.99 × 1023 photons

To what temperature must a balloon, initially at 9°C and 4.00 L, be heated in order to have a volume of 6.00 L?

423 K

Calculate the wavelength (in nm) of the blue light emitted by a mercury lamp with a frequency of 6.32 × 1014 Hz.

475 nm

What mass of NO2 is contained in a 13.0 L tank at 4.58 atm and 385 K?

86.7 g

How many C2H4 molecules are contained in 45.8 mg of C2H4?

9.83 × 1020 C2H4 molecule

Determine the oxidation state of P in PO33-.

+3

Calculate the change in internal energy (ΔE) for a system that is giving off 45.0 kJ of heat and is performing 855 J of work on the surroundings. A) 44.1 kJ

-45.9 kJ

Which of the following (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of heat?

50.0 g Na, CNa = 1.23 J/g°C

Calculate the molar mass of H2CO3.

62.03 g/mol

To what volume (in mL) should you dilute 100.0 mL of a 5.00 M CaCl2 solution to obtain a 0.750 M CaCl2 solution? (Choose the closest numerical value.)

667 mL

How many valence electrons do the halogens (Group 7A) possess?

7

Choose the ground state electron configuration for Zn2⁺.

[Ar]3d10

Give the ground state electron configuration for Sr.

[Kr]5s2

An endothermic reaction has

a positive ΔH, absorbs heat from the surroundings, and feels cold to the touch.

Distillation is

a process in which the more volatile liquid is boiled off.

The nitrogen atom in N2 would be expected to have a

charge of 0.

The current atomic mass scale is based on the adoption of

exactly 12 as the relative atomic mass of the 12C isotope of carbon

A strong acid solution consists of only partially ionized acid molecules.

false

An orbital that penetrates into the region occupied by core electrons is more shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy.

false

Place the following types of electromagnetic radiation in order of increasing wavelength.

gamma rays < ultraviolet light < radio waves

The electronegativity is 2.1 for H and 3.0 for Cl. Based on these electronegativities, H Cl would be expected to

have polar covalent bonds with a partial positive charges on the H atoms.

A cation of +2 indicates that an element has

lost two electrons

Atoms are roughly spherical because when all of the different shaped orbitals are overlapped, they take on a spherical shape.

true

Core electrons effectively shield outer electrons from nuclear charge.

true

Which of the following visible colors of light has the highest frequency?

violet

if the reactants have a higher internal energy than the products, which of the following is /are true?

ΔEsys is negative & Energy flows out of the system into the surroundings.

Give the electron configuration for nitrogen.

1s22s22p3

For n = 3, what are the possible values for l?

0, 1, 2

Determine the molarity of a solution formed by dissolving 468 mg of MgI2 in enough water to yield 50.0 mL of solution.

0.0337 M

How many moles of nitrogen are formed when 58.6 g of KNO3 decomposes according to the following reaction? The molar mass of KNO3 is 101.11 g/mol. 4 KNO3(s) → 2 K2O(s) + 2 N2(g) + 5 O2(g)

0.290 mol N2

A mixture of 10.0 g of Ne and 10.0 g Ar have a total pressure of 1.60 atm. What is the partial pressure of Ar?

0.537 atm

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

0.750 M

Calculate the wavelength of light associated with the transition from in the hydrogen atom.

103nm

Silver has an atomic mass of 107.868 amu. The Ag-109 isotope (108.905 amu) is 48.16%. What is the amu of the other isotope?

106.9 amu

Calculate the mass percent composition of lithium in Li3PO4.

17.98%

Determine the final temperature of a gold nugget (mass = 376 g) that starts at 288 K and loses 4.85 kJ of heat to a snowbank when it is lost. The specific heat capacity of gold is 0.128

187 K

A triple covalent bond contains

3 pairs of electrons.

A substance composed of two or more elements in a fixed, definite proportion is

A compound

What element is undergoing reduction (if any) in the following reaction? Zn(s) + 2 AgNO3(aq) → Zn(NO3)2(aq) + 2 Ag(s)

Ag

The volume of a gas is proportional to number of moles of a gas is known as

Avogadro's Law.

While traveling, an airplane passenger placed a bag of potato chips in his checked luggage. When he opened the luggage, the bag had exploded and potato chips were everywhere in his luggage. Which gas law is this an example of?

Boyle's Law

Which of the following represents a chemical change?

Burning of a candle

Give a possible molecular formula for the empirical formula of C2H5

C4H10N2

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g/mol.

C8H10N4O2

The volume of a gas is proportional to the temperature of a gas is known as

Charles's Law.

Use Lewis theory to determine the chemical formula for the compound formed between K and F.

KF

Place the following elements in order of increasing electronegativity.

Fr < V < C

Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of H2SO4 and KOH are mixed.

H+(aq) + OH-(aq) + 2 K+(aq) + SO42-(aq) → H2O(l) + 2 K+(aq) + SO42-(aq)

An object can exchange energy with other objects by

Heat and work

Three students perform an experiment to determine the density of a salt solution. The students obtain the following results from 4 trials: Student A 10.49 g/mL, 9.79 g/mL, 9.92 g/mL, 10.31 g/mL Student B 9.78 g/mL, 9.82 g/mL, 9.75 g/mL, 9.80 g/mL Student C 10.03 g/mL, 9.99 g/mL, 10.03 g/mL, 9.98 g/mL If the true density of the solution is 10.00 g/mL, which statement below best describes the results for Student C?

Here results are both precise and accurate.

Which reaction below represents the electron affinity of K?

K(g) → K⁺(g) + e⁻

Give the spectator ions for the reaction that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed.

K+ and NO3-

What species is represented by the following information? proton = 12 neutron = 14 electron = 10

Mg +2

Identify the elements correctly shown by decreasing radii size.

N3- > N

Place the following in order of increasing metallic character.

Na < K < Rb < Cs

Identify the substance that conducts electricity.

NaCl dissolved in water

Choose the paramagnetic species from below.

Nb3⁺

Identify the compound with the smallest percent ionic character.

O2

Identify the property of metals that is NOT explained by the electron sea model.

most metals are liquids

Which of the following transitions represent the emission of a photon with the largest energy?

n = 3 to n = 1

Which of the following signs on q and w represent the surroundings that is doing work on the system, as well as losing heat to the surroundings?

q = -, w = +

Which of the following visible colors of light has the longest wavelength?

red

What are the possible orbitals for n = 4?

s, p, d, f