1.4 Energetics

Question 1

What is the definition of a mole?

Answer 1

A mole is the amount of substance that contains as many entities as there are atoms in 12 grams of carbon-12.

Question 2

How many particles are in one mole of a substance?

Answer 2

One mole contains approximately 6.022 x 10^23 particles, known as Avogadro’s number.

Question 3

What is the formula to calculate the number of moles?

Answer 3

The formula to calculate the number of moles is: moles = mass (g) / molar mass (g/mol).

Question 4

True or False: The molar mass of an element is the mass of one mole of that element in grams.

Answer 4

True.

Question 5

Fill in the blank: The molar mass of water (H2O) is _____ g/mol.

Answer 5

18.02

Question 6

What is the term for the mass of one mole of a substance?

Answer 6

Molar mass.

Question 7

What is the molar mass of carbon dioxide (CO2)?

Answer 7

The molar mass of carbon dioxide (CO2) is 44.01 g/mol.

Question 8

What unit is used to measure the amount of substance?

Answer 8

Mole.

Question 9

True or False: The number of moles can be determined from the volume of a gas at standard temperature and pressure (STP).

Answer 9

True.

Question 10

At STP, what is the volume of one mole of an ideal gas?

Answer 10

22.4 liters.

Question 11

What is the equation for calculating the concentration of a solution?

Answer 11

Concentration (mol/dm³) = moles of solute / volume of solution (dm³).

Question 12

Fill in the blank: The concentration of a solution is often expressed in _____ per liter.

Answer 12

moles

Question 13

What is the difference between empirical and molecular formulas?

Answer 13

Empirical formulas show the simplest ratio of elements in a compound, while molecular formulas show the actual number of atoms of each element in a molecule.

Question 14

True or False: The empirical formula of glucose (C6H12O6) is CH2O.

Answer 14

True.

Question 15

What does the term ‘stoichiometry’ refer to?

Answer 15

Stoichiometry refers to the calculation of reactants and products in chemical reactions.

Question 16

What is the limiting reactant in a chemical reaction?

Answer 16

The limiting reactant is the substance that is completely consumed first, limiting the amount of product formed.

Question 17

How can you determine the limiting reactant?

Answer 17

By calculating the number of moles of each reactant and comparing how much product can be formed from each.

Question 18

What does ‘percentage yield’ measure?

Answer 18

Percentage yield measures the efficiency of a reaction by comparing the actual yield to the theoretical yield.

Question 19

What is the formula for calculating percentage yield?

Answer 19

Percentage yield = (actual yield / theoretical yield) x 100.

Question 20

Fill in the blank: Theoretical yield is the maximum amount of product that can be produced from a given amount of reactant, assuming _____.

Answer 20

complete conversion.

Question 21

What is an ionic bond?

Answer 21

An ionic bond is the electrostatic attraction between oppositely charged ions.

Question 22

True or False: Ionic compounds typically have high melting and boiling points.

Answer 22

True.

Question 23

What is a covalent bond?

Answer 23

A covalent bond is a chemical bond formed by the sharing of electrons between atoms.

Question 24

What type of elements typically form covalent bonds?

Answer 24

Nonmetals.

Question 25

What is a mole fraction?

Answer 25

Mole fraction is the ratio of the number of moles of a component to the total number of moles of all components in a mixture.

Question 26

Fill in the blank: The total pressure of a gas mixture can be calculated using _____ law.

Answer 26

Dalton's

Question 27

What does Dalton's Law state?

Answer 27

Dalton's Law states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each gas.

Question 28

What is the relationship between pressure and volume of a gas at constant temperature?

Answer 28

According to Boyle's Law, pressure and volume are inversely related.

Question 29

What does Charles's Law describe?

Answer 29

Charles's Law describes the direct relationship between the volume and temperature of a gas at constant pressure.

Question 30

What is the kinetic molecular theory?

Answer 30

The kinetic molecular theory explains the behavior of gases in terms of particles in motion.

Question 31

What happens to gas pressure when the volume decreases, assuming temperature is constant?

Answer 31

Gas pressure increases.

Question 32

True or False: An increase in temperature generally increases the kinetic energy of gas particles.

Answer 32

True.

Question 33

What is the definition of an ideal gas?

Answer 33

An ideal gas is a theoretical gas that perfectly follows the gas laws without deviation.

Question 34

What does the ideal gas equation relate?

Answer 34

The ideal gas equation relates pressure, volume, temperature, and the number of moles of a gas.

Question 35

What is the ideal gas equation?

Answer 35

PV = nRT.

Question 36

What do the variables in the ideal gas equation stand for?

Answer 36

P = pressure, V = volume, n = number of moles, R = ideal gas constant, T = temperature.

Question 37

Fill in the blank: The value of the ideal gas constant R is _____ J/(mol·K).

Answer 37

8.314

Question 38

What is the relationship between the number of moles and the volume of a gas at constant temperature and pressure?

Answer 38

The volume of a gas is directly proportional to the number of moles.

Question 39

True or False: Real gases behave ideally at high pressures and low temperatures.

Answer 39

False.

Question 40

What is the primary reason real gases deviate from ideal behavior?

Answer 40

Interactions between gas particles and the volume occupied by the gas particles.

Question 41

What is the significance of the Van der Waals equation?

Answer 41

The Van der Waals equation accounts for the volume and intermolecular forces of real gases.

Question 42

What does the term 'saturated solution' refer to?

Answer 42

A saturated solution is one that contains the maximum amount of solute that can dissolve at a given temperature.

Question 43

What is solubility?

Answer 43

Solubility is the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature.