Q: A sample of ice at $$0\ ^\circ\mathrm{C} is $$heated until it becomes steam at $$100\ ^\circ\mathrm{C}. $$Which of the following equations would you use to calculate the energy required to melt the ice?

$$q = m \times \Delta H_{\mathrm{fus}}$$

Q: A solution is prepared by dissolving 10 g of NaCl in 90 g of water. What is the mass percent of NaCl in the solution?

$$\frac{10}{10+90} \times 100\% = 10\%$$

Q: A 2.0 M NaCl solution is diluted to a final volume of 1.0 L. If the initial volume was 0.25 L, what is the final concentration?

$$M_1V_1 = M_2V_2 \implies M_2$ = \frac{2.0 \times 0.25}{1.0} = 0.5\ \mathrm{M}$$

Question 1

Which of the following best explains why water has a higher surface tension than most other liquids?

Accepted Answer

Water molecules form strong hydrogen bonds, which create a cohesive force at the surface.

Question 2

A sample of ice at $$0\ ^\circ\mathrm{C} is $$heated until it becomes steam at $$100\ ^\circ\mathrm{C}. $$Which of the following equations would you use to calculate the energy required to melt the ice?

Accepted Answer

$$q = m 	imes \Delta H_{\mathrm{fus}}$$

Question 3

Which of the following compounds exhibits hydrogen bonding as its strongest intermolecular force?

Accepted Answer

CH$$_3OH ($$methanol)

Question 4

A solution is prepared by dissolving 10 g of NaCl in 90 g of water. What is the mass percent of NaCl in the solution?

Accepted Answer

$$\frac{10}{10+90} 	imes 100\% = 10\%$$

Question 5

Which of the following best describes the process of osmosis?

Accepted Answer

The movement of solvent molecules through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.

Question 6

Which of the following statements about the solubility of gases in water is correct?

Accepted Answer

The solubility of gases in water decreases as temperature increases.

Question 7

Which of the following is an example of an ionic solid?

Accepted Answer

NaCl (sodium chloride)

Question 8

A 2.0 M NaCl solution is diluted to a final volume of 1.0 L. If the initial volume was 0.25 L, what is the final concentration?

Accepted Answer

$$M_1V_1 = M_2V_2 \implies M_2$ = \frac{2.0 	imes 0.25}{1.0} = 0.5\ \mathrm{M}$$

Question 9

Which of the following best describes a saturated solution?

Accepted Answer

A solution in which no more solute can dissolve at a given temperature.

Question 10

Which of the following is a correct statement about the difference between intermolecular forces and chemical bonds?

Accepted Answer

Intermolecular forces are weaker than chemical bonds and occur between molecules, while chemical bonds hold atoms together within a molecule.

Question 11

Which of the following is a hydrocarbon that contains only single bonds?

Accepted Answer

C$$_3H$_8 ($$propane)

Question 12

Which of the following functional groups is present in all amino acids?

Accepted Answer

Both an amino group ($$-\mathrm{NH}_2) $$and a carboxyl group ($$-\mathrm{COOH})$$

Question 13

Which of the following best describes the role of nucleic acids in the body?

Accepted Answer

They store and transmit genetic information.

Question 14

A solution is made by dissolving 0.5 mol of glucose (C$$_6H$_{12}O$_6) in $$enough water to make 1.0 L of solution. What is the molarity of the solution?

Accepted Answer

$$M = \frac{0.5\ \mathrm{mol}}{1.0\ \mathrm{L}} = 0.5\ \mathrm{M}$$

Question 15

Which of the following best explains why carbon can form such a large variety of compounds?

Accepted Answer

Carbon can form four covalent bonds and can bond with itself to form chains and rings.

Question 16

Which of the following is a correct classification for the compound C$$_6H$_{12}O$_6$$?

Accepted Answer

Carbohydrate (monosaccharide)

Question 17

Which of the following statements about the boiling point elevation of a solution is correct?

Accepted Answer

The boiling point of a solution is higher than that of the pure solvent because the solute particles disrupt the vaporization process.

Question 18

Which of the following best describes a peptide bond?

Accepted Answer

A covalent bond formed between the carboxyl group of one amino acid and the amino group of another.

Question 19

A sample of 100 g of water at $$25\ ^\circ\mathrm{C} is $$heated to $$75\ ^\circ\mathrm{C}. If $$the specific heat capacity of water is $$4.18\ \mathrm{J/g\ ^\circ C}$$, how much energy is required for this temperature change?

Accepted Answer

$$q = m 	imes c 	imes \Delta T = 100 	imes 4.18 	imes (75 - 25) = 20,900\ \mathrm{J}$$

Question 20

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar and is double-stranded, while RNA contains ribose sugar and is usually single-stranded.

Intro to Chemistry Midterm Exam Study Guide – Step-by-Step Guidance

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