Post-Lecture Assignment Chapter 5

Calculate the % A.E. (for the product ethanol) for each of the two reactions.

%A.E.(ethylene) = 51.1,100%,

There are 342 g of sucrose in 1.00 mol of sucrose. What is the molar concentration (molarity) of a solution containing 171 g sucrose in 0.750 L solution?

0.667 M

How many moles of sucrose are there in 2.50 L of a 0.500 molar solution?

1.25 mol

Calculate the number of molecules in 3.00 moles H2S.

1.81×1024 H2S molecules

How many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 53.6 moles of water vapor?

107 mol

Calculate the mass of butane needed to produce 56.5 g of carbon dioxide.

18.7 g

Consider the following equation. 2H2O2→2H2O + O2 Explain its meaning at the molecular level.

2 molecules of hydrogen peroxide (H2O2) decompose to form two molecules of water (H2O) and one molecule of oxygen (O2).

Interpret it in terms of moles.

2 moles of hydrogen peroxide (H2O2) decompose to form two moles of water (H2O) and one mole of oxygen (O2).

Consider a 20.0 % (m/v) solution. How can this be written as a conversion factor?

20.0 g of solute/100 mL of solution

Balance the following equations. BaO+O2→BaO2

2BaO+O2→2BaO2

How many moles of H2O are produced when 0.392 mol of octane is burned?

3.53 mol

Balance the following equations. F2+AlCl3→AlF3+Cl2

3F2+2AlCl3→2AlF3+3Cl2

Starting with the partially balanced equation,C4H9OH(g)+O2(g)→?CO2(g)+5H2O(l) what coefficient should be placed in front of CO2 to balance the carbon atoms?

4

How many moles of CO2 are produced when 7.28 mol of oxygen reacts with octane?

4.66 mol

Starting with the unbalanced equation for the combustion of butanol, C4H9OH(g)+O2(g)→CO2(g)+?H2O(l)C4H9OH(g)+O2(g)→CO2(g)+?H2O(l) what coefficient should be placed in front of H2O to balance the hydrogen atoms?

5

Calculate the mass of water produced when 3.74 g of butane reacts with excess oxygen

5.79 g

What is the molar mass of butane, C4H10?

58.12 g/mol

How many moles of methane are produced when 59.6 moles of carbon dioxide gas react with excess hydrogen gas?

59.6 mol

Starting with the partially balanced equation,C4H9OH(g)+?O2(g)→4CO2(g)+5H2O(l) what coefficient should be placed in front of O2 to balance the oxygen atoms?

6

State the mass relationships conveyed by the equation.

68.03 g of hydrogen peroxide (H2O2) decompose to form 36.03 g of water (H2O) and 32.00 g of oxygen (O2).

Calculate the number of moles of Cl atoms in 2.41×1024 formula units of magnesium chloride, MgCl2

8.00 moles Cl

What mass in grams of the magnetic oxide of iron (Fe3O4) can be made from 58.0 g of pure iron and an excess of oxygen? The equation is Fe+O2→Fe3O4 (not balanced)

80.2 g

Ethanol (C2H5OH) is a very important chemical. In addition to being widely used as an industrial solvent, a gasoline additive, and an alternative fuel, it is well known as the alcohol in alcoholic beverages. A common name for ethanol is grain alcohol because it is formed by the fermentation of glucose (C6H12O6) and other sugars in grains such as corn, wheat, and barley: C6H12O6→C2H5OH+CO2 The previous reaction has been carried out for many centuries and is one of the oldest manufacturing processes. In a more recent development, ethanol can be prepared by reacting ethylene (found in petroleum) with water: C2H4+H2O→C2H5OH Write the balanced equation for each of the two reactions above.

C6H12O6→2C2H5OH+2CO2, C2H4+H2O→C2H5OH

Balance the following equations. FeCl2+Na2SiO3→NaCl+FeSiO3

FeCl2+Na2SiO3→2NaCl+FeSiO3

Given the results from parts above, select one of the two methods as the better candidate overall for preparing ethanol.

For industrial purposes, ethylene is presently the most economical method.

Rank the following solutions in increasing order of molarity, overlapping solutions with equivalent molarity.

Lowest molarity: .500 mol of sucrose in 2.00 L of solution 1.00 mol of table salt in 2.00 L of solution .500 mol of glucose in 1.00 L of solution .750 mol of sodium hydroxide in 1.00 L of solution highest molarity

In a combustion reaction, butanol (C4H9OH) is burned in the presence of oxygen (O2), producing carbon dioxide (CO2) and water (H2O). Classify each substance as either a reactant or product in the chemical reaction

Reactants: oxygen butanol Products: carbon dioxide water

Is either method sustainable?

The conversion of glucose is sustainable as it is made from biomass.

How you can determine which reaction has the higher atom economy without doing the calculations above.

The ethylene reaction is balanced as written and all atoms are converted to product.

You have a solution that is 18.5%% (v/v) methyl alcohol. If the bottle contains 1.39 L of solution, what is the volume (V) in milliliters of methyl alcohol?

V = 257 mL

A 6.00 %% (m/v) NaCl solution contains 49.9 g of NaCl. What is the total volume (V) of the solution in milliliters

V = 832 mL

You just determined that when 14 L of ethane (C2H6) and 14 L of oxygen (O2) combined and burned to completion, there is 10 L of excess ethane. In the reaction, 4 L of ethane and 14 L of oxygen burn to completion. What volume of carbon dioxide (CO2) in liters is formed when 4 L of ethane and 14 L of oxygen burn to completion?

Volume of carbon dioxide = 8.00 L

2C2H6(g)+7O2(g)→4CO2(g)+6H2O(g)2C2H6(g)+7O2(g)→4CO2(g)+6H2O(g) In the equation above, what volume of ethane (C2H6) in liters is required to form 28 L L of carbon dioxide (CO2)?

Volume of ethane = 14 L

Ethane burns in air to form carbon dioxide and water. The equation is 2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g) In the above equation, how many liters of oxygen (O2) are required to burn 4.0 L of ethane (C2H6) gas? Assume that both gases are measured at the same temperature and pressure.

Volume of oxygen = 14 L

2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g)2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(g) In the equation, if 14 L of ethane (C2H6) and 14 L of oxygen (O2) combined and burned to completion, which gas will be leftover after the reaction, and what is the volume of that gas remaining?

ethane, 10 L

How many grams (of mass m) of glucose are in 175 mL of a 5.50% (m/v) glucose solution?

m = 9.63 g

What mass in grams of solute is needed to prepare 45.0 mL of 1.65 M C6H12O6?

mass of C6H12O6 = 13.4g

What mass in grams of solute is needed to prepare 8.50 L of 0.100 MM NaOH?

mass of NaOH = 34.0 g

How many atoms of C does the notation 6 Fe(CH3COO)3 indicate?

number of atoms C = 36

How many atoms of Fe does the notation 6 Fe(CH3COO)3 indicate?

number of atoms Fe = 6

How many atoms of H does the notation 6 Fe(CH3COO)3 indicate?

number of atoms H = 54

How many atoms of O does the notation 6 Fe(CH3COO)3 indicate?

number of atoms O = 36

Calculate the amount, in moles, of each of the following. You may round atomic masses to one decimal place. 17.6 g MoO3

the amount = 0.122 mol

Calculate the amount, in moles, of each of the following. You may round atomic masses to one decimal place. 4.58 g CdS

the amount = 3.17×10−2 mol

Calculate the amount, in moles, of each of the following. You may round atomic masses to one decimal place. 882 g AlPO4

the amount = 7.23 mol

Calculate the mass, in grams, of each of the following. You may round atomic masses to one decimal place. 4.56×10−2 mol FeBr3

the mass = 13.5 g

Calculate the mass, in grams, of each of the following. You may round atomic masses to one decimal place. 0.850 mol C6H12O6

the mass = 153 g

Calculate the mass, in grams, of each of the following. You may round atomic masses to one decimal place. 8.00 mol CaCO3

the mass = 801 g

Calculate the molar mass of each of the following compounds. You may round atomic masses to one decimal place. FeSO4

the molar mass = 151.9 gmol

Calculate the molar mass of each of the following compounds. You may round atomic masses to one decimal place. V2O5

the molar mass = 181.8 gmol

Calculate the molar mass of each of the following compounds. You may round atomic masses to one decimal place. Ca(H2PO4)2

the molar mass = 234.1 gmol

Calculate the molar mass of each of the following compounds. You may round atomic masses to one decimal place. (NH4)2Cr2O7

the molar mass = 252.0 gmol

Calculate the percent by mass of N in NaNO3

the percent by mass of N = 16.5 %

Calculate the percent by mass of N in NH4Cl.

the percent by mass of N = 26.2 %

What is the percent by volume concentration of 80.7 mL of acetone in 1550 mL of an acetone-water solution?

the percent by volume concentration of acetone = 5.21%

What is the percent by volume concentration of 17.0 mL of water in 604 mL of an ethanol-water solution?

the percent by volume concentration of water = 2.81%

What volume in liters of 5.75×10−2 M KH2AsO4 contains 1.00 g KH2AsO4?

volume of KH2AsO4 = 9.66×10−2L

What volume in liters of 1.00 M NaOH contains 7.25 mol NaOH?

volume of NaOH = 7.25 L