Q: How many atoms are present in $$2.00$$ moles of magnesium?

$$1.20 \times 10$$^{24}$$ atoms

Question 1

Which of the following is the correct formula for the compound formed between aluminum and sulfate ions?

Accepted Answer

$$\mathrm{Al_2$(SO_4$)_3}$$

Question 2

What is the correct name for the compound $$\mathrm{$$FeCl_3$$}$$?

Accepted Answer

Iron(III) chloride

Question 3

Which of the following ions has a $$-2$$ charge?

Accepted Answer

$$\mathrm{SO_4$^{2-}}$$

Question 4

Calculate the formula mass of $$\mathrm{Mg(OH)_2}$$ given the atomic masses: Mg = $$24.3\ \mathrm{g/mol}$$, O = $$16.0\ \mathrm{g/mol}$$, H = $$1.0\ \mathrm{g/mol}.$$

Accepted Answer

$$58.3\ \mathrm{g/mol}$$

Question 5

Which of the following compounds contains a polyatomic ion?

Accepted Answer

$$\mathrm{$$KNO_3$$}$$

Question 6

How many moles are present in $$18.0\ \mathrm{g} of $$water ($$\mathrm{H_2O}$$)? (Molar mass of $$\mathrm{H_2O} = 18.0\ \mathrm{g/mol})$$

Accepted Answer

$$1.00$$ mole

Question 7

What is the correct formula for ammonium phosphate?

Accepted Answer

$$\mathrm{(NH_4$)_3PO_4}$$

Question 8

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$\mathrm{$$CO_2$$}$$. How many moles of $$\mathrm{$$CO_2$$}$$ are present?

Accepted Answer

$$0.50$$ moles

Question 9

Which of the following is the correct name for $$\mathrm{Na_2SO_4}$$?

Accepted Answer

Sodium sulfate

Question 10

What is the empirical formula for a compound containing $$40.0\%$$ carbon, $$6.7\%$$ hydrogen, and $$53.3\%$$ oxygen by mass?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 11

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

Accepted Answer

$$\mathrm{Ca(NO_3$)_2}$$

Question 12

How many atoms are present in $$2.00$$ moles of magnesium?

Accepted Answer

$$1.20 	imes 10$$^{24}$$ atoms

Question 13

Which of the following is the correct name for $$\mathrm{H_2SO_4}$$?

Accepted Answer

Sulfuric acid

Question 14

What is the molar mass of $$\mathrm{Ca_3$(PO_4$)_2}$$? (Ca = $$40.1$$, P = $$31.0$$, O = $$16.0)$$

Accepted Answer

$$310.2\ \mathrm{g/mol}$$

Question 15

Which of the following ions is a cation?

Accepted Answer

$$\mathrm{NH_4$^+}$$

Question 16

A compound contains $$27.3\%$$ carbon and $$72.7\%$$ oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 17

Which of the following is the correct formula for iron(II) sulfate?

Accepted Answer

$$\mathrm{$$FeSO_4$$}$$

Question 18

How many formula units are present in $$0.25$$ moles of $$\mathrm{NaCl}$$?

Accepted Answer

$$1.51 	imes 10$$^{23}$$

Question 19

Which of the following is the correct name for $$\mathrm{K_2Cr_2O_7}$$?

Accepted Answer

Potassium dichromate

Question 20

A $$5.00\ \mathrm{g}$$ sample of $$\mathrm{NaCl}$$ contains how many moles? (Molar mass of $$\mathrm{NaCl} = 58.5\ \mathrm{g/mol})$$

Accepted Answer

$$0.0855$$ moles

Writing and Predicting Chemical Formulas, Stoichiometry, and Nomenclature: Study Notes for Introduction to Chemistry

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