Q: Which of the following is the correct expression for the enthalpy change of a reaction using bond energies?

$$\Delta H = \sum D_{\text{bonds broken}} - \sum D_{\text{bonds formed}}$$

Q: Which of the following is the correct formula for calculating the formal charge on an atom in a Lewis structure?

$$\text{Formal charge} = \text{valence electrons} - (\text{lone pairs} + \frac{1}{2} \times \text{bonding electrons})$$

Q: Which of the following is the correct expression for the standard enthalpy change of a reaction using enthalpies of formation?

$$\Delta H^\circ_{rxn} = \sum \Delta H^\circ_f(\text{products}) - \sum \Delta H^\circ_f(\text{reactants})$$

Question 1

Which of the following statements best describes the difference between the molecular geometry and the electron domain geometry of a molecule?

Accepted Answer

Molecular geometry considers only the arrangement of atoms, while electron domain geometry considers both atoms and lone pairs around the central atom.

Question 2

Given the reaction: $$\mathrm{$$CaCO_3$$(s) + 2HCl(aq) \rightarrow $$CaCl_2$$(aq) + CO_2$(g) + H_2O(l)}$$, how many liters of $$\mathrm{CO_2$}$$ gas at 0.875 atm and 31°C can be produced from 10.0 g of $$\mathrm{$$CaCO_3$$}$$? (R = 0.0821 L·atm·mol$$^{-1}$$·K$$^{-1}$$, Molar mass of $$\mathrm{$$CaCO_3$$} = 100.1 g/$$mol)

Accepted Answer

$$2.98 L$$

Question 3

Which of the following compounds is expected to have a molecular dipole moment?

Accepted Answer

$$\mathrm{$$ICL_3$$}$$

Question 4

A sample of He gas (2.0 mmol) effuses through a pinhole in 53 s. The same amount of an unknown gas effuses in 246 s. What is the molar mass of the unknown gas?

Accepted Answer

$$85.5 g/$$mol

Question 5

Which of the following best describes the effect of increasing temperature on the solubility of most solid ionic compounds in water?

Accepted Answer

Solubility increases with increasing temperature.

Question 6

What is the frequency (in Hz) of electromagnetic radiation with a wavelength of $$361.3 nm$$? (Speed of light $$c = 2.9979 	imes 10^8$ m/s)

Accepted Answer

$$8.295 	imes 10$$^{14}$$ Hz

Question 7

Which of the following is the correct net ionic equation for the reaction between $$\mathrm{K_3PO_4(aq)}$$ and $$\mathrm{$$AgNO_3$$(aq)}$$?

Accepted Answer

$$\mathrm{PO_4$^{3-}(aq) + 3Ag^+(aq) \rightarrow Ag_3PO_4(s)}$$

Question 8

Which of the following statements about the molecular orbital diagram for $$\mathrm{NO} is $$correct?

Accepted Answer

$$\mathrm{NO}$$ has one unpaired electron and is paramagnetic.

Question 9

A solution is prepared by mixing 70.0 mL of 0.100 mol/L HCl and 30.0 mL of 0.200 mol/L NaCl. What is the molarity of chloride ion in the final solution?

Accepted Answer

$$0.130$$ mol/L

Question 10

Which of the following is the correct expression for the enthalpy change of a reaction using bond energies?

Accepted Answer

$$\Delta H = \sum D_{	ext{bonds broken}} - \sum D_{	ext{bonds formed}}$$

Question 11

Which of the following salts is insoluble in water according to the solubility rules provided?

Accepted Answer

$$\mathrm{AgCl}$$

Question 12

What is the final temperature of a 30.0 g gold nugget (specific heat $$0.128 J/g$$·°C) initially at 200.0°C that loses 425 J of heat to a snowbank?

Accepted Answer

$$88.6$$ °C

Question 13

Which of the following is the correct formula for calculating the root-mean-square speed ($$u_{rms}) of a $$gas molecule?

Accepted Answer

$$u_{rms} = \sqrt{\frac{3RT}{M}}$$

Question 14

Which of the following is the correct balanced molecular equation for the reaction between $$\mathrm{K_3PO_4(aq)}$$ and $$\mathrm{$$AgNO_3$$(aq)}$$?

Accepted Answer

$$\mathrm{K_3PO_4(aq) + 3AgNO_3(aq) \rightarrow Ag_3PO_4(s) + 3KNO_3(aq)}$$

Question 15

Which of the following is the correct formula for calculating the formal charge on an atom in a Lewis structure?

Accepted Answer

$$	ext{Formal charge} = 	ext{valence electrons} - (	ext{lone pairs} + \frac{1}{2} 	imes 	ext{bonding electrons})$$

Question 16

Which of the following gases will have the highest root-mean-square speed at 298 K?

Accepted Answer

$$\mathrm{H_2$}$$

Question 17

Which of the following is the correct expression for the standard enthalpy change of a reaction using enthalpies of formation?

Accepted Answer

$$\Delta H^\circ_{rxn} = \sum \Delta H^\circ_f(	ext{products}) - \sum \Delta H^\circ_f(	ext{reactants})$$

Question 18

Which of the following is the correct balanced redox equation for the reaction between $$\mathrm{H_2O_2(aq)}$$ and $$\mathrm{Cl_2$(g)} in $$acidic solution?

Accepted Answer

$$\mathrm{H_2O_2(aq) + Cl_2$(g) \rightarrow 2HCl(aq) + O_2$(g)}$$

General Chemistry I: Comprehensive Study Notes and Reference Tables

Guida di studio - Domande di pratica

Study guide - Flashcard