Q: How many individual oxygen atoms are present in $$6.05 g of$$ $$\mathrm{Mg(NO_3$)_2}$$? (Molar mass $$= 148.33 g/$$mol)

$$1.47 \times 10$$^{23}$$ atoms

Question 1

Which of the following statements best describes the difference between metals, nonmetals, and metalloids as classified on the periodic table?

Accepted Answer

Metals are good conductors and malleable, nonmetals are poor conductors and tend to gain electrons, and metalloids have intermediate properties.

Question 2

Which of the following elements is a metalloid?

Accepted Answer

Boron (B)

Question 3

What is the correct name for the compound $$\mathrm{$$CoCl_2$$ \cdot 6H_2O}$$?

Accepted Answer

Cobalt(II) chloride hexahydrate

Question 4

Which of the following is the correct formula for aluminum bromite?

Accepted Answer

$$\mathrm{Al($$BrO_2$$)_3}$$

Question 5

How many moles of oxygen atoms are present in $$0.089 g of $$sulfuric acid ($$\mathrm{H_2SO_4}$$)? (Molar mass of $$\mathrm{H_2SO_4}$$ = $$98.09 g/$$mol)

Accepted Answer

$$0.0036$$ mol

Question 6

Which of the following compounds is a Type III (covalent) compound?

Accepted Answer

$$\mathrm{CO} ($$carbon monoxide)

Question 7

What is the correct name for $$\mathrm{$$HClO_4$$} (aq$$)?

Accepted Answer

Perchloric acid

Question 8

A sample contains $$8.371 	imes 10$$^{21}$$ molecules and has a mass of 0.888$ g. What is the molar mass of the substance?

Accepted Answer

$$64.0 g/$$mol

Question 9

Which of the following is the correct formula for calcium acetate?

Accepted Answer

$$\mathrm{Ca(CH_3COO)_2}$$

Question 10

Which of the following best describes the difference between an ionic and a covalent compound?

Accepted Answer

Ionic compounds are formed by the electrostatic attraction between cations and anions, while covalent compounds involve the sharing of electrons between nonmetals.

Question 11

How many individual oxygen atoms are present in $$6.05 g of$$ $$\mathrm{Mg(NO_3$)_2}$$? (Molar mass $$= 148.33 g/$$mol)

Accepted Answer

$$1.47 	imes 10$$^{23}$$ atoms

Question 12

Which of the following is a diatomic element in its natural state?

Accepted Answer

Nitrogen ($$\mathrm{N_2$})$$

Question 13

What is the molar mass of oxalic acid dihydrate ($$\mathrm{H_2C_2O_4 \cdot 2H_2O}$$)? (Atomic masses: H = 1.01, C = 12.01, O = 16.00)

Accepted Answer

$$126.07 g/$$mol

Question 14

Which of the following is the correct name for $$\mathrm{Fe(NO_3$)_2 \cdot 6H_2O}$$?

Accepted Answer

Iron(II) nitrate hexahydrate

Question 15

A sample of $$\mathrm{Ca_3$(PO_4$)_2}$$ contains $$4.8 	imes 10$$^{25}$$ oxygen atoms. How many kilograms of calcium phosphate are in the sample? (Molar mass = 310.18$ g/mol)

Accepted Answer

$$3.1 kg$$

Question 16

Which of the following is the correct name for $$\mathrm{P_2O_5}$$?

Accepted Answer

Diphosphorus pentoxide

Question 17

What is the charge on the ion typically formed by magnesium?

Accepted Answer

$$2+$$

Question 18

Which of the following best describes a hydrate?

Accepted Answer

An ionic compound containing a specific number of water molecules per formula unit.

Question 19

What is the correct name for $$\mathrm{H_2SO_3}$$?

Accepted Answer

Sulfurous acid

Question 20

If you have $$25.0 mL of $$acetone ($$\mathrm{CH_3COCH_3}) $$with a density of $$784 kg/m$^3$$, how many moles of acetone are present? (Molar mass $$= 58.08 g/$$mol)

Accepted Answer

$$0.34$$ mol

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