chemistry Test Worksheet: Table I Heats Of Reaction At 101.3 Kpa And 298 K

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Chemistry worksheet
Topic: Table I Heats Of Reaction At 101.3 Kpa And 298 K

Table I Heats Of Reaction At 101.3 Kpa And 298 K

Given the balanced equation representing a reaction occurring at 101.3 kilopascals and 298 K:

2H₂(g) + O₂(g) → 2H₂O(ℓ) + energy

What is the net amount of energy released when one mole of H₂O(ℓ) is produced?

(1) 241.8 kJ

(2) 285.8 kJ

(3) 483.6 kJ

(4) 571.6 kJ

At 101.3 kPa and 298 K, what is the total amount of heat released when one mole of aluminum oxide, Al₂O₃(s), is formed from its elements?

(1) 393.5 kJ

(2) 837.8 kJ

(3) 1676 kJ

(4) 3351 kJ

According to Table I, which equation represents a change resulting in the greatest quantity of energy released?

(1) 2C(s) + 3H₂(g) → C₂H₆(g)

(2) 2C(s) + 2H₂(g) → C₂H₄(g)

(3) N₂(g) + 3H₂(g) → 2NH₃(g)

(4) N₂(g) + O₂(g) → 2NO(g)

Based on Table I, what is the ∆H value for the production of 1.00 mole of NO₂(g) from its elements at 101.3 kPa and 298 K?

(1) +33.2 kJ

(2) −33.2 kJ

(3) +132.8 kJ

(4) −132.8 kJ

Based on Table I, which equation represents a reaction with the greatest difference between the potential energy of the products and the potential energy of the reactants?

(1) 4Al(s) + 3O₂(g) → 2Al₂O₃(s)

(2) 2H₂(g) + O₂(g) → 2H₂O(ℓ)

(3) C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(ℓ)

(4) C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(ℓ)

Based on Table I, which equation represents conservation of mass and energy?

(1) CH₄(g) + O₂(g) + 890.4 kJ → CO₂(g) + H₂O(ℓ)

(2) CH₄(g) + O₂(g) → CO₂(g) + H₂O(ℓ) + 890.4 kJ

(3) CH₄(g) + 2O₂(g) + 890.4 kJ → CO₂(g) + 2H₂O(ℓ)

(4) CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(ℓ) + 890.4 kJ

Base your answers to questions 7 on the information below.

Ammonium chloride is dissolved in water to form a 0.10 M NH₄Cl(aq) solution. This dissolving process is represented by the equation below.

physical-behavior-of-matter, concentration-of-a-solution fig: chem12013-exam_g18.png

State evidence that indicates the dissolving of ammonium chloride is an endothermic process.

Allow 1 credit. Acceptable responses include, but are not limited to:

• The process requires heat to dissolve NH₄Cl.

• Energy is absorbed as NH₄Cl dissolves.

• The energy term is positive on the left side of the equation arrow.

• The heat of reaction is positive.

Base your answers to questions 8 on the information below and on your knowledge of chemistry.

In a laboratory activity, each of four different masses of KNO₃(s) is placed in a separate test tube that contains 10.0 grams of H₂O at 25°C.

When each sample is first placed in the water, the temperature of the mixture decreases. The mixture in each test tube is then stirred while it is heated in a hot water bath until all of the KNO₃(s) is dissolved. The contents of each test tube are then cooled to the temperature at which KNO₃ crystals first reappear. The procedure is repeated until the recrystallization temperatures for each mixture are consistent, as shown in the table below.

kinetics-equilibrium, heat-of-reaction-amd-potential-energy-diagram, physical-behavior-of-matter, physical-change-and-chemical-change fig: chem82018-exam_g10.png

Based on Table I, explain why there is a decrease in temperature when the KNO₃(s) was first dissolved in the water.

Allow 1 credit. Acceptable responses include, but are not limited to:

• The solution would decrease in temperature because the dissolving of KNO₃(s) is endothermic.

• The heat of solution is positive, which means the mixture would decrease in temperature.

• The ∆H is + 34.89 kJ, so KNO₃(s) requires energy to dissolve.

Base your answers to questions 9 on the information below and on your knowledge of chemistry.

In the early 1900s, scientists developed a process to produce ammonia from hydrogen and atmospheric nitrogen on an industrial scale. The balanced equation below represents this reaction.

N₂(g) + 3H₂(g) → 2NH₃(g) + 91.8 kJ

At room temperature, the reaction occurs at a very slow rate. Therefore, this process takes place in a special reaction vessel at high temperature and high pressure. A catalyst is used to increase the rate of the production of ammonia. The reaction gases are cooled to remove the ammonia as a liquid and the remaining gases are sent back to the reaction vessel.

Using the axes shown below, draw a potential energy diagram for the reaction. [1]

kinetics-equilibrium, heat-of-reaction-amd-potential-energy-diagram, kinetics-equilibrium, heat-of-reaction-amd-potential-energy-diagram fig: chem12024-ansbklt_abkq1.png

Allow 1 credit for showing that the PE of the products is lower than the PE of the reactants.

•

Base your answers to questions 10 on the information below and on your knowledge of chemistry.

During a laboratory activity, a student dissolves 20.0 grams of solid ammonium chloride, NH₄Cl(s), in 100.0 grams of water at 25°C. After thorough stirring, no undissolved NH₄Cl(s) remains. During this laboratory activity, appropriate safety equipment is used and safety procedures are followed.

State evidence from Table I that indicates that this dissolving process is endothermic. [1]

Allow 1 credit. Acceptable responses include, but are not limited to:

• The nH for this dissolving is 114.78 kJ/mol.

• The heat of solution is positive.

Base your answers to questions 11 on the information below and on your knowledge of chemistry.

Hydrogen gas and iodine gas can combine in a reversible reaction to form hydrogen iodide gas. The equation below represents this system at equilibrium in a sealed, rigid container.

physical-behavior-of-matter, physical-change-and-chemical-change fig: chem82023-exam_g16.png

State evidence from the equation that the forward reaction is endothermic. [1]

Allow 1 credit. Acceptable responses include, but are not limited to:

• The equation shows energy on the reactant side.

• Energy is on the left side of the equation.

• The 53 kJ is on the left side.

• heat term on reactant side