Q: A pint of beer (500 mL) contains 25 mL alcohol. What is the percent alcohol by volume (ABV)?

$$\frac{25}{500} \times 100 = 5\%$$

Q: What is the percent sugar by mass in hummingbird food containing 20 g sugar and 80 g water?

$$\frac{20}{100} \times 100 = 20\%$$

Q: How many grams of NaNO$$_3$$ are needed to make 430 g of an aqueous solution that is 4.85% by mass NaNO$$_3$$?

$$\frac{4.85}{100} \times 430 = 20.86 g$$

Q: Which equation correctly represents molarity?

$$M = \frac{\text{moles of solute}}{\text{liters of solution}}$$

Q: A saline solution contains 0.15 M NaCl. What is the mass of NaCl required to prepare 0.750 L of this solution? (Molar mass of NaCl = 58.44 g/mol)

$$0.15 \times 0.750 \times 58.44 = 6.57 g$$

Q: Which of the following best describes the relationship between mass, moles, and molar mass?

$$\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}$$

Question 1

Which of the following best describes a solution in chemistry?

Accepted Answer

A homogeneous mixture in which the solvent is present in the largest amount and the solute is dissolved within it.

Question 2

Given the reaction $$\mathrm{CaO} + \mathrm{H_2O} \rightarrow \mathrm{Ca(OH)_2}$$, what are the reactants?

Accepted Answer

CaO and H$$_2O$$

Question 3

How much water, in grams, is needed to produce 2 kg of Ca(OH)$$_2 in $$the reaction $$\mathrm{CaO} + \mathrm{H_2O} \rightarrow \mathrm{Ca(OH)_2}$$? (Molar mass of water = 18 g/mol, CaO = 56 g/mol, Ca(OH)$$_2 = 74 g/$$mol)

Accepted Answer

486 g

Question 4

What is the molarity ($$M) of a $$solution prepared by dissolving 0.15 mol NaCl in 0.750 L of water?

Accepted Answer

$$M = \frac{0.15}{0.750} = 0.20$$

Question 5

A pint of beer (500 mL) contains 25 mL alcohol. What is the percent alcohol by volume (ABV)?

Accepted Answer

$$\frac{25}{500} 	imes 100 = 5\%$$

Question 6

What is the percent sugar by mass in hummingbird food containing 20 g sugar and 80 g water?

Accepted Answer

$$\frac{20}{100} 	imes 100 = 20\%$$

Question 7

How many grams of NaNO$$_3$$ are needed to make 430 g of an aqueous solution that is 4.85% by mass NaNO$$_3$$?

Accepted Answer

$$\frac{4.85}{100} 	imes 430 = 20.86 g$$

Question 8

Which of the following is the correct conversion for 3 ppm to decimal form?

Accepted Answer

0.000003

Question 9

Which state of matter is characterized by particles that are far apart and move randomly and rapidly?

Accepted Answer

Gas

Question 10

What is the process called when a solid changes directly to a gas?

Accepted Answer

Sublimation

Question 11

Which intermolecular force is the strongest in holding matter in the condensed states?

Accepted Answer

Ionic bonds

Question 12

Which of the following best describes a concentrated solution?

Accepted Answer

A solution with a large amount of solute in a given amount of solvent.

Question 13

Which equation correctly represents molarity?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 14

Which intermolecular force is responsible for the attraction between polar molecules?

Accepted Answer

Dipole forces

Question 15

A saline solution contains 0.15 M NaCl. What is the mass of NaCl required to prepare 0.750 L of this solution? (Molar mass of NaCl = 58.44 g/mol)

Accepted Answer

$$0.15 	imes 0.750 	imes 58.44 = 6.57 g$$

Question 16

Which of the following is NOT a type of intermolecular force?

Accepted Answer

Covalent bonds

Question 17

What is the process called when a liquid becomes a gas at its boiling point?

Accepted Answer

Vaporization

Question 18

Which of the following is a correct statement about the freezing point and melting point of a substance?

Accepted Answer

The freezing point and melting point are the same temperature.

Question 19

Which of the following best describes the relationship between mass, moles, and molar mass?

Accepted Answer

$$	ext{moles} = \frac{	ext{mass (g)}}{	ext{molar mass (g/mol)}}$$

Lecture 15

Guida di studio - Domande di pratica

Study guide - Flashcard