Chapter 3 Homework

Question 1

How many atoms would be found in 1.2 grams of copper?

Answer 1

1.1 × 10^22 copper atoms

Question 2

In the graphic below is a balanced chemical equation describing the reaction between nitrogen and hydrogen to form ammonia. How would this balanced chemical equation be written using molecular formulas for each compound?

Answer 2

N2 + 3H2 -> 2NH3

Question 3

What is the molar mass of glucose, C6H12O6?

Answer 3

180.155 grams / mole

Question 4

An ointment used for treating burns, silver sulfadiazine (AgC10H9N4SO2 ) is formed in the following reaction:

AG2O + 2C10H10N4SO2 -> 2AGC10H9N4SO2 + H2O

What mass of silver oxide (Ag2O) is needed to prepare 225 grams of silver sulfadiazine (molar mass = 357.14 g / mol) from sulfadiazine (C10H10N4SO2 )?

Answer 4

73.0 g Ag2O

Question 5

What is the coefficient for water in the properly balanced equation for the combustion of butane and oxygen gas to form carbon dioxide gas and water according to the equation:

C4H10 + O2 → CO2 + H2O

Answer 5

10

Question 6

What is the mass of the oxygen in 2.0 moles of silver nitrate (AgNO3)?

Answer 6

96 grams

Question 7

How many moles (mol) are represented by 4.70 × 10^26 atoms of uranium?

Answer 7

7.80 × 10^2 mol

Question 8

Phosphorus pentoxide is used as a drying agent because it reacts with water to form phosphoric acid:

P4O10 + H2O → H3PO4 

Which equation is balanced for this reaction?

Answer 8

P4O10 + 6H2O → 4H3PO4

Question 9

Ammonia (NH3) is produced industrially using the Haber-Bosch process (1912) which combines nitrogen (N2) and hydrogen (H2) at high temperatures (500°C) and high pressures (200 atm). What is the theoretical yield of ammonia (NH3) that can be produced when a cylinder containing 50.0 kg of nitrogen gas (N2) is reacted with excess hydrogen gas (H2)?

Answer 9

60.8 kilograms (3570 moles).

Question 10

Using the balanced chemical equation shown, how many grams of FeCl3 are produced from 425.4 g of Cl2 and excess Fe(s)?

2Fe(s) + 3Cl2(g) → 2FeCl3(s)

Answer 10

648.8 g FeCl3

Question 11

23.10 grams of aluminum metal are dissolved in a solution that contains 1.89 mol of hydrochloric acid to yield aluminum chloride (AlCl3 ) and hydrogen gas according to the following balanced chemical equation. What is the limiting reactant?

2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)

Answer 11

HCl

Question 12

Using the following balanced chemical equation, determine the limiting reactant in the reaction between 3.0 grams of titanium and 8.0 grams of chlorine gas?

Ti(s) + 2Cl2(g) → TiCl4(s)

Answer 12

Cl2

Question 13

What mass of titanium(IV) chloride could be formed from the reaction of 3.00 g titanium and 8.00 grams of chlorine gas (Cl2 )?

Use the following balanced chemical equation:

Ti(s) + 2Cl2(g) → TiCl4(s)

Answer 13

10.6 g titanium(IV) chloride

Question 14

Potassium chlorate (KClO3, FW = 122.55) may be decomposed quantitatively to KCl and oxygen gas (O2). How much KClO3 would be required to yield 10.0 grams of KCl (FW = 74.55)?

Answer 14

16.4 grams

Question 15

What is the percentage yield of Fe2O3 if you begin with 3.2 moles FeO and 1 mol O2 if the actual yield is 110.3 g Fe2O3?
The reaction below might need balancing.

FeO(s) + O2(g) → Fe2O3(s)

Answer 15

43.2%

Question 16

An unknown pesticide is made up of 18.28% carbon, 0.77% hydrogen, and 80.95% chlorine. What is the empirical formula of the pesticide?

Answer 16

C2HCl3

Question 17

Which of the following equations is properly balanced, including having the smallest whole number coefficients?

Answer 17

2Na + 2H2O → 2NaOH + H2

Question 18

How many moles of ethanol are contained in 57.38 grams of ethanol (C2H5OH)?

Answer 18

1.246 moles ethanol

Question 19

A reaction vessel contains 20.0 grams of sodium metal and 10.0 grams of chlorine gas. The reaction to produce sodium chloride has gone to 100% completion. Which is the excess reagent and how much of it remains?

Answer 19

sodium. 0.588 moles (13.5 grams) of sodium remains unreacted.

Question 20

How many moles of iodine are produced from 7.00 moles of chlorine, according to the equation shown?

3Cl2(g) + 2FeI2(s) → 2FeCl3(s) + 2I2(g)

Answer 20

4.67 mol