Question 1

Given the unbalanced reaction: $$Fe_2O_3 + H_2SO_4 \rightarrow Fe_2$(SO_4$)_3 + H_2O$$, if you start with 8.20 g of $$Fe_2O_3$$ and produce 0.0885 moles of $$Fe_2$$($$SO_4)_3$ in a 23.6% yield, how many moles of Fe_2O_3$ did you actually start with?

Accepted Answer

$$0.0515$$ mol

Question 2

You have 30.0 g of an unknown compound. After dissolving it in 150.0 mL of water, you add 50.0 mL of the solution to a new flask. If there are 0.750 moles of the compound in the diluted solution, what is the experimental molar mass?

Accepted Answer

$$40.0 \ g/mol$$

Question 3

A student mixes 50.0 mL of NaOH solution of unknown molarity with 175.0 mL of 0.800 M $$H_2SO_4. $$The reaction is $$2NaOH + H_2SO_4 \rightarrow Na_2SO_4 + 2H_2O. If $$the final mixture contains 0.140 mol of sodium sulfate, what was the molarity of the original NaOH solution? Assume 100% yield.

Accepted Answer

$$2.80 \ M$$

Question 4

Which of the following is the correct formula for dinitrogen tetroxide?

Accepted Answer

$$N_2O_4$$

Question 5

How many moles of sulfur atoms are present in 12.5 grams of $$P_4S_8$$?

Accepted Answer

$$0.263$$ mol

Question 6

Balance the following chemical reaction: $$C_4H_{10} + O_2$ \rightarrow CO_2$ + H_2O$$

Accepted Answer

$$2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O$$

Question 7

You react 0.70 moles of Al with 0.34 moles of $$Fe_2O_3$$ according to $$2Al + Fe_2O_3 \rightarrow Al_2O_3 + 2Fe. $$What is the limiting reagent?

Accepted Answer

$$Fe_2O_3$$

Question 8

If you mix 40.0 mL of 0.300 M NaOH with 120.0 mL of water, what is the final concentration of NaOH?

Accepted Answer

$$0.0750 \ M$$

Question 9

What is the electron configuration for the $$Ti^{3+}$$ ion?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$ $$3p^6$$ $$3d^1$$

Question 10

Why does oxygen have a smaller ionization energy than nitrogen, despite having a larger effective nuclear charge ($$Z_{eff}$$)?

Accepted Answer

Electron-electron repulsion in the paired 2p orbital of oxygen lowers its ionization energy.

Question 11

Arrange the elements C, Fe, Mo, and Pd in order from largest to smallest atomic radius.

Accepted Answer

Mo \u003e Pd \u003e C \u003e Fe

Question 12

Which of the following is the condensed electron configuration for $$Nb$$?

Accepted Answer

$$[Kr] 5s^1$ 4d^4$

Question 13

For the elements S, Li, and C, which has the largest electronegativity?

Accepted Answer

S

Question 14

Which transition in an energy level diagram would result in the absorption of a photon?

Accepted Answer

An electron moving from a lower to a higher energy orbital

Question 15

What is the full electron configuration for $$Si$$?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$ $$3p^2$$

Question 16

Which of the following compounds is iron(III) sulfate?

Accepted Answer

$$Fe_2$$($$SO_4)_3$

Question 17

If you have 0.300 M NaOH and mix 40.0 mL with 160.0 mL of water, what is the final concentration?

Accepted Answer

$$0.0750 \ M$$

Question 18

Which of the following is the correct formula for potassium carbonate?

Accepted Answer

$$K_2CO_3$$

Question 19

Which element has the largest ionization energy among S, Li, and C?

Accepted Answer

C

General Chemistry: Stoichiometry, Solutions, Electron Configuration, and Periodic Trends

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