1. Suppose you used a thermite reaction to heat the beverage. How many grams of iron(III) oxide would be needed? (Molar mass: 159.69 g/mol)

Fe2O3 + 2 Al â 2 Fe + Al2O3 ÎH = â547.5 kJ/mol

A. 115 g

B. 11 g

C. 20 g

D.

591 g

2. How many grams of calcium oxide do we need for this reaction?

CaO (s) + H2O (l) â Ca(OH)2 (aq) ÎH = â63.7 kJ/mol

A. 56 g

B. 33 g

C. 130 kg

D.

0.010 g

3. The relationship between the heat absorbed by the beverage and the heat generated by the reaction is given by:

A. Qbeverage = âTbeverage

B. Qbeverage = Qreaction

C. Qbeverage = -Qreaction

D. Qbeverage = âHreaction

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Related questions

Question 1

Iron is made from a reaction of iron oxide with carbon monoxide in the following reaction:

Fe2O3(s) + 3 CO(g) â 2 Fe(s) + 3 CO2(g)

Using Hess' Law, calculate the enthalpy of reaction given:

C(s) + O2(g) â CO2(g) ÎH = -393.5 kJ/mol

2 Fe(s) + 3/2 O2(g) â Fe2O3(s) ÎH = -824.2 kJ/mol

C(s) + 1/2 O2(g) â CO(g) ÎH = -110.5 kJ/mol

Question 2

Use Hess' Law to calculate enthalpy of reaction for the following equation:

2 N2(g) + 5 O2(g) â 2 N2O5(g)

Given:

2 H2(g) + O2(g) â 2 H2O(l) ÎH = -571.6 kJ/mol

N2O5(g) + H2O(l) â 2 HNO3(l) ÎH = -76.6 kJ/mol

1/2 N2(g) + 3/2 O2(g) + 1/2 H2(g) â HNO3(l) ÎH = -174.1 kJ/mol

Question 3

Using standard enthalpies of formation, determine the ÎHreaction for the following equations:

2 CH3OH(l) + 3 O2(g) â 2 CO2(g) + 4 H2O(g)

Show your work for all calculations.

1. When 1.104 grams of iron metal are mixed with 26.023 grams of hydrochloric acid in a coffee cup calorimeter, the temperature rises from 25.2 Â°C to a maximum of 33.5 Â°C. The reaction that occurs is given below.

2Fe(s)+6HCl(aq) â 2FeCl3 (aq)+3H2 (g)

a) Determine the amount of heat (in J) absorbed by the reaction mixture. Assume that the specific heat capacity of the mixture is the same as the specific heat capacity of water.

b) How much heat (in J) was released by the reaction that occurred?

c) Is this reaction exothermic or endothermic? Is ÎHreaction positive or negative?

d) Under constant pressure conditions (as used in this experiment), the heat released by the reaction equals the reaction enthalpy, qreleased = ÎHreaction. Determine ÎHreaction in Joules per gram of metal used (J/g).

e) Determine ÎHreaction in kilojoules per mole of metal used (kJ/mol).

f) Determine ÎHreaction in kilojoules per mole for the balanced reaction equation provided (kJ/mol). ï¿¼ï¿¼ï¿¼ï¿¼ï¿¼ï¿¼ï¿¼

2. Consider the following three reactions:

2Fe(s)+6HCl(aq) â 2FeCl3 (aq)+3H2 (g) ÎHA

Fe2O3 (s)+6HCl(aq) â 2FeCl3 (aq)+3H2O(l) ÎHB

2H2 (g) + O2 (g) â 2H2O(l) ÎHC

Show how these equations must be summed together according to Hessâs Law to determine ÎH for the combustion of iron (target equation shown below). Also show clearly how the ÎH values of each of the three reactions must be manipulated to determine the enthalpy of combustion of iron.

4Fe(s)+3O2 (g) â 2Fe2O3 (s) ÎH=?

3. Using tabulated ÎHfÂ° values in the text, determine the enthalpy change (in kJ/mol) that occurs during the formation of water from its elements as described by the equation:

2H2 (g) + O2 (g) â 2H2O(l) ÎH=?