# Which answer choice represents BOTH the correct temperature of the block in Kelvin AND the correct density of the block in g/cm³

20/25  that’s 80%

RETAKE

1

A 150.0 mg block at 22.5⁰C has a volume of 5,382 cm³.

Which answer choice represents BOTH the correct temperature of the block in Kelvin AND the correct density of the block in g/cm³?

• 72.5 ⁰K; 2.78 x 10⁻⁵ g/cm³
• 296 ⁰K; 2.78 x 10⁻⁵ g/cm³
• 296 ⁰K; 3.59 x 10⁴ g/cm³
• -250 ⁰K; 3.59 x 10⁻⁴ g/cm³

## RATIONALE

Convert ⁰C to ⁰K by adding 273.15. Since d = m/v, both mass and volume are needed (in grams and cubic centirmeters, respectively, since that is the desired density unit in the question). Convert mg to g to determine mass.

## CONCEPT

Dimensional Analysis

2

The trapping of heat within the atmosphere is known as the _____ effect.

• climate
• anthropogenic
• greenhouse

## CONCEPT

Greenhouse Gases

3

Which type of battery is most commonly used in automobiles?

• lithium-ion
• hydrogen fuel cell

## CONCEPT

Chemical Reactions in the Real World

4

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

The pressure of a sample of gas is measured with an open-end manometer. The liquid in the manometer is mercury, and the liquid level on the left side is 6.00 in. higher than the liquid level on the right side (assume the gas chamber is on the left side).

Assuming atmospheric pressure is 29.92 in. Hg, determine the pressure of the gas in kPa.

• 608 kPa
• 81,100 kPa
• 0.811 kPa
• 81.1 kPa

## RATIONALE

29.92 in. Hg – 6.00 in. Hg = 23.92 in. Hg. So, 23.92 in. Hg x (760 torr / 29.92 in. Hg) x (101325 Pa / 760 torr) x (1 kPa / 1,000 Pa) = 81.1 kPa

## CONCEPT

Introduction to Gases

5

An alternate way to state Avogadro’s law is, “All other things being equal, the number of molecules in a gas is _____ the volume of the gas.”

• unaffected by
• inversely proportional to
• equal to
• directly proportional to

## CONCEPT

Gas Laws

6

Which is the weakest intermolecular force?

• hydrogen bonding
• dipole-dipole
• electrostatic
• dispersion

## CONCEPT

Intermolecular Forces

7

Which of the following atoms has the largest atomic radius?

• I
• At
• Sr
• Ba

## CONCEPT

Periodic Trends

8

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

is known as ________.

## CONCEPT

Introduction to Nuclear Chemistry

9

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

Two balloons are filled with two different gases. Balloon A deflates faster than Balloon B.

This best demonstrates which of the following?

• Kinetic Molecular Theory
• Graham’s law of effusion
• diffusion
• mean free path

## CONCEPT

Diffusion, Effusion, and Kinetic Molecular Theory

10

Which of the following must be present with a weak base to make a buffer?

• strong base
• strong acid
• conjugate acid
• acetate

## CONCEPT

Buffers

11

Which of these pairs of atoms would experience a polar covalent bond?

• P and S
• C and O
• K and Br
• Cl and Cl

## RATIONALE

This would be a polar covalent bond, since it is a bond between two nonmetals whose differences in electronegativity values are in the polar covalent range.

## CONCEPT

Chemical Bonding

12

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

When Ca(OH)₂ reacts with H₂SO₄ what are the products?

• Ca(OH)₂ and H₂SO₄
• CaSO₄ and H₂O
• CO₂ and H₂O
• CaO and H₂SO₄

## RATIONALE

The products of a neutralization reaction are salt and water. The salt is formed from the cation of the base and the anion of the acid. In this case, the cation of the base is Ca²⁺ and the anion of the acid is SO₄²⁻, so the salt will be CaSO₄.

## CONCEPT

Acid and Base Reactions

13

When an object experiences a change that causes heat to be released, it is known as a(n) ________ process.

• exothermic
• conservation
• endothermic
• specific heat

## CONCEPT

Energy Basics

14

As a wave’s frequency increases, its energy ______.

• disappears
• stays the same
• increases
• decreases

## CONCEPT

Bohr Model

15

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

If 4.12 L of a 0.850 M H₃PO₄ solution is to be diluted to a volume of 10.00 L, what is the concentration of the resulting solution?

• 0.350 M
• 0.485 M
• 2.06 M
• 35.0 M

## RATIONALE

C₂ = (C₁ x V₁) / V₂ = (0.850 M x 4.12 L) / 10.00 L = 0.350 M

## CONCEPT

Calculations with Solutions

16

According to Dalton’s theory, __________.

• atoms are the smallest units of matter
• compounds are comprised of one element
• elements can consist of different types of atoms
• atoms can be created or destroyed in chemical reactions

## CONCEPT

History of Atomic Theory

17

At the largest solar thermal power plant in the world, what chemical is used as the working fluid?

• sodium chloride
• proteins
• water
• sodium acetate

## CONCEPT

Energy in Our World

18

The value of the entropy change for the process N₂ (g) + 3H₂ (g) –> 2NH₃ (g) is ________.

• unchanged
• zero
• positive
• negative

## RATIONALE

The process results in a net decrease in the amount of gaseous speciesand thus a decreased dispersal of matter, therefore an decrease (negative direction) in entropy.

## CONCEPT

Laws of Thermodynamics

19

Which form of electromagnetic radiation is most responsible for converting oxygen into ozone?

• infrared
• visible light
• ultraviolet
• microwaves

## CONCEPT

Ozone Layer

20

To answer this question, you may need access to the periodic table of elements, a calculator, and the equations and charts in the tutorial associated with this question.

C₃H₈ (g) + 5O₂ (g) –> 3CO₂ (g) + 4H₂O (l) would be best classified as which type of reaction?

• combustion
• single displacement
• acid-base
• precipitation

## RATIONALE

Propane is the reductant (fuel) and oxygen is the oxidant, producing carbon dioxide and water, so this is a combustion reaction.

## CONCEPT

Introduction to Reactions

21

Which of the following correctly expresses the value of 0.0149 in scientific notation AND in the SI unit for density?

• 1.49 x
• 1.49 x  g/mol
• 1.49 x  g/mol
• 1.49 x

## RATIONALE

To convert to scientific notation, place the decimal after the first non-zero number. This yields 1.49. To get the decimal to this location, you moved 2 spots to the right (meaning a negative exponent), so 1.49 x . The SI unit for density is kilogram per cubic meter ().

## CONCEPT

Scientific Notation and Units of Measurement

22

A compound that is defined by its ability to produce hydroxide ions when dissolved in water is known as a(n) _____.

• Lewis base
• Arrhenius base
• Brønsted-Lowry base
• conjugate acid

## CONCEPT

Molecular Definitions of Acids and Bases

23

If combustion happens in a scenario where the pressure can remain constant (i.e. in an open system), the heat produced is ________ ΔH.

• less than
• greater than
• not related to
• equal to

## CONCEPT

Matter and Energy

24

Which of these is the cycle for the most abundant compound on Earth?

• oxygen
• phosphorus
• carbon
• hydrological

## CONCEPT

Chemical Cycles

25

A 2.50‑L volume of hydrogen measured at –196 °C is warmed to 100 °C.

Calculate the volume of the gas at the higher temperature, assuming no change in pressure.

• 4.9 L
• 0.517 L
• 12.1 L
• 1.28 L

## RATIONALE

Apply Charles’s law to compute the volume of gas at the higher temperature (V₂), being sure to convert from Celsius to Kelvin by adding 273.15: V₂ = V₁T₂ / T₁ = [(2.50 L)(373.15 K)] / 77.15 K] = 12.1 L

## CONCEPT

Calculations Using Gas Laws

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