Q: How many oxygen atoms are there in $$3.00\ \mathrm{g} of $$sodium dichromate, $$\mathrm{Na}_2\mathrm{Cr}_2\mathrm{O}_7$$? The molar mass of sodium dichromate is $$261.97\ \mathrm{g/mol}.$$

$$4.83 \times 10$$^{22}$$ oxygen atoms

Question 1

A compound containing only C, H, and O is combusted, producing $$14.50\ \mathrm{mg} of$$ $$\mathrm{CO}_2$$ and $$5.93\ \mathrm{mg} of$$ $$\mathrm{H}_2\mathrm{O}$$ from $$6.53\ \mathrm{mg} of $$the compound. What is the empirical formula of the compound?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 2

Which blocks of the periodic table contain the main-group elements?

Accepted Answer

p & s

Question 3

Which of the following is an alkaline earth metal?

Accepted Answer

Magnesium

Question 4

Give the mass percent of hydrogen in $$\mathrm{C}_{14}\mathrm{H}_{19}\mathrm{NO}_2.$$

Accepted Answer

$$8.22\%$$

Question 5

Which of the following compounds is NOT correctly classified?

Accepted Answer

$$\mathrm{CH}_3\mathrm{CH}_2\mathrm{OH}$$, inorganic molecular compound

Question 6

Which of the following describes a double covalent bond?

Accepted Answer

Two electron pairs shared between atoms

Question 7

How many core and valence electrons are in a neutral atom of gallium ($$\mathrm{Ga}$$)?

Accepted Answer

28 core electrons, 3 valence electrons

Question 8

Which of the following statements is correct regarding effective nuclear charge ($$Z_{\mathrm{eff}}$$)?

Accepted Answer

Rb atoms are larger than K atoms.

Question 9

Place the following in order of increasing first ionization energy ($$IE_1$$): $$\mathrm{N}$$, $$\mathrm{F}$$, $$\mathrm{As}.$$

Accepted Answer

$$\mathrm{As} \u003c \mathrm{N} \u003c \mathrm{F}$$

Question 10

Antimony is used in some antiparasitic medications. What type of element is antimony ($$\mathrm{Sb}$$)?

Accepted Answer

Metalloid

Question 11

How many dots appear around Si in the Lewis electron-dot structure for the silicon atom?

Accepted Answer

4

Question 12

Give the complete electronic configuration for Mn.

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^2$$ $$3p^6$$ $$3d^5$$ $$4s^2$$

Question 13

A period 3 element has the following ionization energies (all in $$\mathrm{kJ/mol}$$): $$IE_1 = 786.5$, IE_2$ = 1577$$, $$IE_3 = 3232$, IE_4$ = 4356$$, $$IE_5 = 16091$. Which element is it?

Accepted Answer

P

Question 14

How many oxygen atoms are there in $$3.00\ \mathrm{g} of $$sodium dichromate, $$\mathrm{Na}_2\mathrm{Cr}_2\mathrm{O}_7$$? The molar mass of sodium dichromate is $$261.97\ \mathrm{g/mol}.$$

Accepted Answer

$$4.83 	imes 10$$^{22}$$ oxygen atoms

Question 15

Determine the molecular formula of a compound that has a molar mass of $$305.3\ \mathrm{g/mol}$$ and an empirical formula of $$\mathrm{C}_2\mathrm{H}_5\mathrm{O}_2.$$

Accepted Answer

$$\mathrm{C}_{10}\mathrm{H}_{25}\mathrm{O}_{10}$$

Question 16

Which of the following characteristics apply to a paramagnetic substance?

Accepted Answer

At least one electron is unpaired; Attracted to a magnetic field

Question 17

Write the name for $$\mathrm{IBr}_5.$$

Accepted Answer

Iodine pentabromide

Question 18

What is the empirical formula for a species that is composed of sulfur and oxygen with $$57.19\% of $$the mass coming from sulfur?

Accepted Answer

$$\mathrm{SO}_2$$

Question 19

Which element would most likely form an ion with a charge of $$-3$$?

Accepted Answer

P

Question 20

Which has the smallest radius?

Accepted Answer

$$\mathrm{F}^-$$

General Chemistry Exam Review: Atomic Structure, Periodic Table, Chemical Bonding, and Stoichiometry

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