Q: A 2.00 L sample of nitrogen gas at 25°C and 1.00 atm is heated to 75°C at constant pressure. What is the final volume of the gas? (Assume ideal behavior.)

$$V_2$$ = $$V_1$$ \times \frac{$$T_2$$}{$$T_1$$}$$, so V_2$ = 2.00\,\text{L} \times \frac{348.15\,\text{K}}{298.15\,\text{K}} = 2.34\,\text{L}$$

Q: A 25.0 mL sample of 0.200 M H2SO4 is titrated with 0.100 M NaOH. What volume of NaOH is required to reach the equivalence point? (Assume complete neutralization.)

$$\text{H}_2\text{SO}_4 + 2\text{NaOH} \rightarrow 2\text{H}_2\text{O} + \text{Na}_2\text{SO}_4$$; $$n_{\text{H}_2$$\text{SO}_4} = 0.0250\,\text{L} \times 0.200\,\text{mol/L} = 0.00500\,\text{mol}$$; n$$_{\text{NaOH}} = 2 \times 0.00500 = 0.0100\,\text{mol}$$; V$$ = \frac{0.0100\,\text{mol}}{0.100\,\text{mol/L}} = 0.100\,\text{L} = 100\,\text{mL}$$

Q: A 5.00 g sample of copper metal (Cu, $$M = 63.55\,\text{g/mol}) is $$heated with 500 J of energy. If the specific heat capacity of copper is $$0.385\,\text{J/g} \cdot \text{K}$$, what is the temperature change of the copper?

$$\Delta T = \frac{500}{5.00 \times 0.385} = 25.97\,\text{K}$$

Q: A 10.0 g sample of CaCO3 reacts with excess HCl to produce CO2 gas. What volume of CO2 (at STP) is produced? ($$M_{\text{CaCO}_3$$} = 100.09\,\text{g/mol}$$)

$$n = \frac{10.0}{100.09} = 0.0999\,\text{mol}$$; $$V = n \times 22.4\,\text{L} = 2.24\,\text{L}$$

Q: A 1.00 L container holds a mixture of 0.50 mol N2 and 0.50 mol O2 at 298 K. If the total pressure is 2.46 atm, what is the partial pressure of O2?

Mole fraction O2 = 0.50/(0.50+0.50) = 0.50; $$P_{\text{O}_2$$} = 0.50 \times 2.46 = 1.23\,\text{atm}$$

Question 1

A sample of a compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of this compound?

Accepted Answer

CH2O

Question 2

Which of the following statements about the molecule O2 is correct according to molecular orbital (MO) theory?

Accepted Answer

O2 is paramagnetic due to two unpaired electrons in its π* orbitals.

Question 3

A 2.00 L sample of nitrogen gas at 25°C and 1.00 atm is heated to 75°C at constant pressure. What is the final volume of the gas? (Assume ideal behavior.)

Accepted Answer

$$V_2$$ = $$V_1$$ 	imes \frac{$$T_2$$}{$$T_1$$}$$, so V_2$ = 2.00\,	ext{L} 	imes \frac{348.15\,	ext{K}}{298.15\,	ext{K}} = 2.34\,	ext{L}$$

Question 4

Which of the following compounds is expected to be insoluble in water?

Accepted Answer

PbCl2

Question 5

A 25.0 mL sample of 0.200 M H2SO4 is titrated with 0.100 M NaOH. What volume of NaOH is required to reach the equivalence point? (Assume complete neutralization.)

Accepted Answer

$$	ext{H}_2	ext{SO}_4 + 2	ext{NaOH} ightarrow 2	ext{H}_2	ext{O} + 	ext{Na}_2	ext{SO}_4$$; $$n_{	ext{H}_2$$	ext{SO}_4} = 0.0250\,	ext{L} 	imes 0.200\,	ext{mol/L} = 0.00500\,	ext{mol}$$; n$$_{	ext{NaOH}} = 2 	imes 0.00500 = 0.0100\,	ext{mol}$$; V$$ = \frac{0.0100\,	ext{mol}}{0.100\,	ext{mol/L}} = 0.100\,	ext{L} = 100\,	ext{mL}$$

Question 6

Which of the following molecules has a trigonal pyramidal molecular geometry?

Accepted Answer

NH3

Question 7

A 5.00 g sample of copper metal (Cu, $$M = 63.55\,	ext{g/mol}) is $$heated with 500 J of energy. If the specific heat capacity of copper is $$0.385\,	ext{J/g} \cdot 	ext{K}$$, what is the temperature change of the copper?

Accepted Answer

$$\Delta T = \frac{500}{5.00 	imes 0.385} = 25.97\,	ext{K}$$

Question 8

Which of the following is the correct electron configuration for the Fe$$^{3+}$$ ion?

Accepted Answer

$$[	ext{Ar}]\,3d^5$

Question 9

Which of the following statements about the Lewis structure of the nitrate ion, NO3$$^-$$, is correct?

Accepted Answer

There are three equivalent resonance structures, each with a double bond to a different oxygen.

Question 10

A 10.0 g sample of CaCO3 reacts with excess HCl to produce CO2 gas. What volume of CO2 (at STP) is produced? ($$M_{	ext{CaCO}_3$$} = 100.09\,	ext{g/mol}$$)

Accepted Answer

$$n = \frac{10.0}{100.09} = 0.0999\,	ext{mol}$$; $$V = n 	imes 22.4\,	ext{L} = 2.24\,	ext{L}$$

Question 11

Which of the following best explains why the boiling point of H2O is much higher than that of H2S?

Accepted Answer

H2O forms strong hydrogen bonds due to the high electronegativity of oxygen.

Question 12

Which of the following is the correct set of quantum numbers for the last electron added to a phosphorus atom (Z = 15) in its ground state?

Accepted Answer

$$n = 3,\ l = 1,\ m_l = 1,\ m_s = +\frac{1}{2}$$

Question 13

Which of the following statements about the molecule SF4 is correct?

Accepted Answer

SF4 has a seesaw molecular geometry due to one lone pair on the central atom.

Question 14

A 1.00 L container holds a mixture of 0.50 mol N2 and 0.50 mol O2 at 298 K. If the total pressure is 2.46 atm, what is the partial pressure of O2?

Accepted Answer

Mole fraction O2 = 0.50/(0.50+0.50) = 0.50; $$P_{	ext{O}_2$$} = 0.50 	imes 2.46 = 1.23\,	ext{atm}$$

Question 15

Which of the following best describes the hybridization of the central atom in XeF4?

Accepted Answer

sp$$^3d$^2$$

Question 16

Which of the following is the net ionic equation for the reaction between aqueous solutions of Na2SO4 and BaCl2?

Accepted Answer

$$	ext{Ba}^{2+}(aq) + 	ext{SO}_4$$^{2-}$$(aq) ightarrow 	ext{BaSO}_4(s)$$

Question 17

Which of the following is the correct bond order for the N2 molecule according to molecular orbital theory?

Accepted Answer

3

Question 18

Which of the following best explains why CO2 is a nonpolar molecule, even though it contains polar bonds?

Accepted Answer

CO2 has a linear geometry, so the bond dipoles cancel each other.

General Chemistry I: Comprehensive Study Guide (Chapters 1–11)

Guida di studio - Domande di pratica

Study guide - Flashcard