Q: How many molecules of water are produced when $$20.0\,\mathrm{kg} of $$glucose combusts completely? (Avogadro's number: $$6.022 \times 10$$^{23}$$ molecules/mol)

$$2.41 \times 10$$^{27}$$ molecules

Question 1

Which balanced chemical equation correctly represents the reaction between sodium metal and chlorine gas to produce sodium chloride?

Accepted Answer

$$2\,\mathrm{Na} + \mathrm{Cl}_2 \rightarrow 2\,\mathrm{NaCl}$$

Question 2

How many moles of chlorine gas ($$\mathrm{Cl}_2) $$are required to completely react with 10.0 g of sodium metal ($$\mathrm{Na}) $$according to the equation $$2\,\mathrm{Na} + \mathrm{Cl}_2 \rightarrow 2\,\mathrm{NaCl}$$?

Accepted Answer

$$0.217$$ moles

Question 3

What is the mass of chlorine gas ($$\mathrm{Cl}_2) $$needed to react with 10.0 g of sodium metal ($$\mathrm{Na}) to $$form sodium chloride ($$\mathrm{NaCl}$$)? (Molar mass: $$\mathrm{Na} = 22.99\,\mathrm{g/mol}$$, $$\mathrm{Cl}_2 = 70.90\,\mathrm{g/mol})$$

Accepted Answer

$$3.09\,\mathrm{g}$$

Question 4

Sodium nitrate ($$\mathrm{NaNO}_3) $$decomposes according to the equation: $$2\,\mathrm{NaNO}_3 \rightarrow 2\,\mathrm{NaNO}_2 + \mathrm{O}_2. $$How many moles of $$\mathrm{NaNO}_3$$ are required to produce $$128\,\mathrm{g} of$$ $$\mathrm{O}_2$$?

Accepted Answer

$$4.00$$ moles

Question 5

What is the mass of sodium nitrate ($$\mathrm{NaNO}_3) $$required to produce $$128\,\mathrm{g} of $$oxygen gas ($$\mathrm{O}_2) $$via decomposition? (Molar mass: $$\mathrm{NaNO}_3 = 85.00\,\mathrm{g/mol}$$, $$\mathrm{O}_2 = 32.00\,\mathrm{g/mol})$$

Accepted Answer

$$340\,\mathrm{g}$$

Question 6

Glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6) $$combusts in excess oxygen according to the equation: $$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\,\mathrm{O}_2 \rightarrow 6\,\mathrm{CO}_2 + 6\,\mathrm{H}_2\mathrm{O}. $$How many moles of carbon dioxide ($$\mathrm{CO}_2) $$are produced from $$20.0\,\mathrm{kg} of $$glucose? (Molar mass: $$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 = 180\,\mathrm{g/mol})$$

Accepted Answer

$$667$$ moles

Question 7

How many molecules of water are produced when $$20.0\,\mathrm{kg} of $$glucose combusts completely? (Avogadro's number: $$6.022 	imes 10$$^{23}$$ molecules/mol)

Accepted Answer

$$2.41 	imes 10$$^{27}$$ molecules

Question 8

If $$2.40\,\mathrm{g} of $$magnesium reacts with $$10.0\,\mathrm{g} of $$oxygen gas, what is the limiting reactant? (Molar masses: $$\mathrm{Mg} = 24.3\,\mathrm{g/mol}$$, $$\mathrm{O}_2 = 32.0\,\mathrm{g/mol})$$

Accepted Answer

Magnesium

Question 9

Calculate the mass of magnesium oxide ($$\mathrm{MgO}) $$produced when $$2.40\,\mathrm{g} of $$magnesium reacts with $$10.0\,\mathrm{g} of $$oxygen gas. (Molar mass: $$\mathrm{MgO} = 40.3\,\mathrm{g/mol})$$

Accepted Answer

$$3.98\,\mathrm{g}$$

Question 10

A patient is exposed to $$128\,\mathrm{g} of $$oxygen gas produced from the decomposition of sodium nitrate. How many moles of sodium nitrite ($$\mathrm{NaNO}_2) $$are formed? (Reaction: $$2\,\mathrm{NaNO}_3 \rightarrow 2\,\mathrm{NaNO}_2 + \mathrm{O}_2)$$

Accepted Answer

$$8.00$$ moles

Question 11

If $$10.0\,\mathrm{g} of $$sodium metal reacts with excess chlorine gas, what mass of sodium chloride ($$\mathrm{NaCl}) is $$produced? (Molar mass: $$\mathrm{NaCl} = 58.44\,\mathrm{g/mol})$$

Accepted Answer

$$25.4\,\mathrm{g}$$

Question 12

Which of the following best describes the type of reaction when sodium nitrate decomposes to sodium nitrite and oxygen gas?

Accepted Answer

Decomposition

Question 13

A fire in a hospital laboratory involves the combustion of glucose. If $$20.0\,\mathrm{kg} of $$glucose is burned, how many grams of carbon dioxide ($$\mathrm{CO}_2) $$are produced? (Molar mass: $$\mathrm{CO}_2 = 44.0\,\mathrm{g/mol})$$

Accepted Answer

$$29,348\,\mathrm{g}$$

Question 14

Which of the following statements is true regarding the stoichiometry of the reaction $$2\,\mathrm{Na} + \mathrm{Cl}_2 \rightarrow 2\,\mathrm{NaCl}$$?

Accepted Answer

Two moles of sodium react with one mole of chlorine gas to produce two moles of sodium chloride.

Question 15

If $$2.40\,\mathrm{g} of $$magnesium reacts with $$10.0\,\mathrm{g} of $$oxygen gas, what is the theoretical yield of magnesium oxide ($$\mathrm{MgO}) in $$moles? (Molar mass: $$\mathrm{MgO} = 40.3\,\mathrm{g/mol})$$

Accepted Answer

$$0.0988$$ moles

Question 16

A student claims that $$10.0\,\mathrm{g} of $$sodium metal will produce $$10.0\,\mathrm{g} of $$sodium chloride when reacted with chlorine gas. Is this correct? Why or why not?

Accepted Answer

No, because the mass of sodium chloride produced will be greater due to the addition of chlorine.

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