Question 1

Which of the following best explains why $$\mathrm{CO_2$} is a $$greenhouse gas, but $$\mathrm{N_2$}$$ and $$\mathrm{O_2$}$$ are not?

Accepted Answer

$$\mathrm{CO_2$}$$ absorbs infrared radiation due to symmetry breaking in its vibrational modes, while $$\mathrm{N_2$}$$ and $$\mathrm{O_2$} do $$not have symmetry breaking and thus cannot absorb IR efficiently.

Question 2

A solution is prepared by dissolving $$0.50\ \mathrm{mol} of$$ $$\mathrm{NaCl} in $$enough water to make $$1.0\ \mathrm{L} of $$solution. What is the molarity of the solution?

Accepted Answer

$$0.50\ \mathrm{M}$$

Question 3

Which of the following reactions is a formation reaction?

Accepted Answer

$$\mathrm{C(s) + O_2$(g) \rightarrow CO_2$(g)}$$

Question 4

A $$25.0\ \mathrm{mL}$$ sample of $$0.200\ \mathrm{M}$$ $$\mathrm{HCl} is $$titrated with $$0.100\ \mathrm{M}$$ $$\mathrm{NaOH}. $$What volume of $$\mathrm{NaOH} is $$required to reach the equivalence point?

Accepted Answer

$$50.0\ \mathrm{mL}$$

Question 5

Which of the following best describes a strong electrolyte?

Accepted Answer

A substance that completely dissociates into ions when dissolved in water.

Question 6

Given the reaction: $$\mathrm{2H_2(g) + O_2$(g) \rightarrow 2H_2O(l)}$$, if $$4.0\ \mathrm{mol} of$$ $$\mathrm{H_2$}$$ and $$2.0\ \mathrm{mol} of$$ $$\mathrm{O_2$}$$ are mixed, what is the limiting reactant?

Accepted Answer

$$\mathrm{O_2$}$$

Question 7

Which of the following is the correct net ionic equation for the reaction between $$\mathrm{Na_2SO_4(aq)}$$ and $$\mathrm{$$BaCl_2$$(aq)}$$?

Accepted Answer

$$\mathrm{Ba$$^{2+}$$(aq) + SO_4$^{2-}(aq) \rightarrow $$BaSO_4$$(s)}$$

Question 8

Which of the following statements about the First Law of Thermodynamics is correct?

Accepted Answer

The internal energy change of a system, $$\Delta E$$, is equal to the heat added to the system plus the work done on the system: $$\Delta E = q + w$$

Question 9

A $$50.0\ \mathrm{g}$$ sample of water absorbs $$418\ \mathrm{J} of $$heat. What is the temperature change? ($$c = 4.18\ \mathrm{J\ g$$^{-1}$$\ ^\circ C$$^{-1}$$})$$

Accepted Answer

$$2.00\ ^\circ \mathrm{C}$$

Question 10

Which of the following is the correct oxidation number for nitrogen in $$\mathrm{NO_2$}$$?

Accepted Answer

$$+4$$

Question 11

Which of the following best describes why water has a high 'water footprint' in industrial processes?

Accepted Answer

Water's high specific heat allows it to absorb and transfer large amounts of energy, making it essential for temperature regulation and cooling.

Question 12

Which of the following is a correct application of Hess's Law?

Accepted Answer

The enthalpy change for a reaction can be calculated by summing the enthalpy changes of multiple steps that add up to the overall reaction.

Question 13

Which of the following is the correct molecular equation for the neutralization of $$\mathrm{$$HNO_3$$(aq)}$$ with $$\mathrm{KOH(aq)}$$?

Accepted Answer

$$\mathrm{$$HNO_3$$(aq) + KOH(aq) \rightarrow $$KNO_3$$(aq) + H_2O(l)}$$

Question 14

A $$10.0\ \mathrm{g}$$ sample of $$\mathrm{C_3H_8} is $$combusted in excess $$\mathrm{O_2$}. $$What is the theoretical yield of $$\mathrm{CO_2$} (in $$grams)? (Molar mass $$\mathrm{C_3H_8} = 44.1\ \mathrm{g/mol}$$, $$\mathrm{CO_2$} = 44.0\ \mathrm{g/mol}$$, reaction: $$\mathrm{C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O})$$

Accepted Answer

$$29.9\ \mathrm{g}$$

Question 15

Which of the following best describes a precipitation reaction?

Accepted Answer

A reaction in which two aqueous solutions combine to form an insoluble solid.

Question 16

Which of the following is the correct expression for Beer's Law?

Accepted Answer

$$A = \varepsilon b c$$

Question 17

Which of the following is a correct statement about oxidation and reduction?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 18

A $$100.0\ \mathrm{mL}$$ solution of $$0.500\ \mathrm{M}$$ $$\mathrm{NaCl} is $$diluted to $$250.0\ \mathrm{mL}. $$What is the final concentration?

Accepted Answer

$$0.200\ \mathrm{M}$$

Question 19

Which of the following best describes a state function?

Accepted Answer

A property that depends only on the initial and final states of a system, not on the path taken.

Question 20

Which of the following ions is a spectator ion in the reaction between $$\mathrm{Na_2SO_4(aq)}$$ and $$\mathrm{$$BaCl_2$$(aq)}$$?

Accepted Answer

$$\mathrm{Na^+}$$

Chemistry 1770 Exam 3 Study Guide: Stoichiometry, Solution Chemistry, and Energy

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