Question 1

Which of the following measurements is correctly reported with the appropriate number of significant figures, given the data: 12.30 g + 0.045 g + 1.2 g?

Accepted Answer

13.5 g

Question 2

A sample of gas occupies 2.50 L at 25°C. What will be its volume at 75°C, assuming constant pressure? (Use Charles' Law: $$\frac{V_1$}{T_1$} = \frac{V_2$}{T_2$}$$, temperatures in Kelvin)

Accepted Answer

2.93 L

Question 3

Which of the following best describes the difference between a colloid and a suspension?

Accepted Answer

Colloid particles are smaller than suspension particles and do not settle out upon standing.

Question 4

Which of the following is a chemical change?

Accepted Answer

Rusting of iron

Question 5

A radioactive isotope has a half-life of 4 hours. If you start with 80 mg, how much remains after 12 hours?

Accepted Answer

10 mg

Question 6

Which of the following statements about alpha ($$\alpha$$), beta ($$\beta$$), and gamma ($$\gamma) $$radiation is correct?

Accepted Answer

Beta radiation consists of electrons and can be stopped by aluminum foil.

Question 7

Which of the following is the correct IUPAC name for the compound with the formula $$\mathrm{CH_3CH_2CH_2CH_3}$$?

Accepted Answer

Butane

Question 8

A solution is prepared by dissolving 5.0 g of NaCl in enough water to make 250 mL of solution. What is the molarity of the solution? ($$\mathrm{NaCl}$$ molar mass = 58.44 g/mol)

Accepted Answer

$$0.34\ \mathrm{M}$$

Question 9

Which of the following best describes the role of a buffer in a biological system?

Accepted Answer

A buffer maintains pH by reacting with small amounts of added acid or base.

Question 10

Which of the following is the correct Lewis structure for water ($$\mathrm{H_2O}$$)?

Accepted Answer

O atom with two single bonds to H atoms and two lone pairs on O

Question 11

Which of the following is the correct classification for the reaction: $$\mathrm{2H_2 + O_2$ \rightarrow 2H_2O}$$?

Accepted Answer

Combination (synthesis) reaction

Question 12

A sample contains 12 protons, 12 neutrons, and 10 electrons. What is the symbol for this ion?

Accepted Answer

$$^{24}\mathrm{Mg}^{2+}$$

Question 13

Which of the following functional groups is present in acetone ($$\mathrm{CH_3COCH_3}$$)?

Accepted Answer

Ketone

Question 14

Which of the following best explains why oil does not dissolve in water?

Accepted Answer

Oil is nonpolar and water is polar, so their intermolecular forces are not compatible.

Question 15

A solution has $$[H_3O^+] = 1 	imes 10$$^{-5}$$\ \mathrm{M}. $$What is its pH?

Accepted Answer

5

Question 16

Which of the following is the oxidizing agent in the reaction: $$\mathrm{Zn + Cu$$^{2+}$$ \rightarrow Zn$$^{2+}$$ + Cu}$$?

Accepted Answer

$$\mathrm{Cu$$^{2+}$$}$$

Question 17

Which laboratory safety procedure should you follow if you spill a strong acid on your skin?

Accepted Answer

Rinse immediately with plenty of water and notify your instructor.

Question 18

Which of the following best describes the effect of increasing the temperature on the solubility of a solid in water?

Accepted Answer

Solubility generally increases with temperature.

Question 19

Which of the following is the correct balanced equation for the neutralization of hydrochloric acid with sodium hydroxide?

Accepted Answer

$$\mathrm{HCl + NaOH \rightarrow NaCl + H_2O}$$

Question 20

A student measures the mass of a beaker as 45.67 g, adds a sample, and the total mass is 48.12 g. What is the mass of the sample, reported with the correct number of significant figures?

Accepted Answer

2.45 g

Comprehensive Study Guide for General, Organic, and Biological Chemistry Final Exam

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