WorksheetsThermochemistry _2
Total questions: 15
Worksheet time: 13mins
A chemical reaction that absorbs heat from the surroundings is said to be __________ and has a __________ ΔH at constant pressure.
(a)
The reaction 4Al (s) + 3O2 (g) ---> 2Al2O3 (s)
ΔHe = -3351 kJ
is __________, and therefore heat is __________ by the reaction.
(a)
The value of ΔH for the reaction below is -126 kJ. How much heat (in kJ) is released when 2.00 mol of NaOH is formed in the reaction?
Na2O2 (s) + H2O (l) ---> NaOH (s) + O2 (g)
(a)
The specific heat of liquid bromine is 0.226 J/g-K. How much heat (J) is required to raise the temperature of 10.0 mL of bromine from 25.00°C to 27.30°C? The density of liquid bromine: 3.12 g/mL.
(a)
Given the following reactions
Fe2O3 (s) + 3CO (s) --> 2Fe (s) + 3CO2 (g) ∆H = -28.0 kJ
3Fe (s) + 4CO2 (s) --> 4CO (g) + Fe3O4 (s) ∆H = +12.5 kJ
What is enthalpy of the reaction of Fe2O3 with CO in
3Fe2O3 (s) + CO (g) à CO2 (g) + 2Fe3O4 (s) ?
(a)
What happens to the value of ∆H for a thermochemical reaction if the reaction is reversed?
(a)
If a solid is converted from liquid to gas, then entropy is (a) .
If value of change in free energy is less than zero then the reaction will be referred as (a) .
Translate the word description below into balance thermochemical equation:
The heat of formation of sodium carbonate is -1056 kJ
A reaction is performed in a beaker with a temperature probe recording the temperature changes of the reaction. If the temperature began at 15.0 degrees Celsius and ended at 27.5 degrees Celsius. If the reaction is our system, is the system endothermic or exothermic?
(a)
Do reactants in an endothermic reaction have a higher or lower energy than the products?
(a)
4 PCl5 + 3438 kJ --> P4 + 10 Cl2
How much energy is required to produce each mole of chlorine?
(a)
In a laboratory experiment a student was using Styrofoam cups and foil to reduce the energy lost during an exothermic reaction. The reaction constantly had a temperature probe in it. Towards the end of the reaction the student noticed the temperature in the cups was going down (opposite what they thought is should). The student concluded that the energy was destroyed within the system. This student's reasoning violates what law?
(a)
H2 + Cl2 --> 2 HCl + 1845 kJ
Is this reaction endothermic or exothermic?
(a)
What mass of P4 must be reacted to produce 5905 kJ of energy?
P4 + 6Cl2 --> 4PCl3 + 2439 kJ
(a)
