1.16 Unit Test Chemical Thermodynamics
Question: Unless otherwise instructed, you may use a scientific calculator and refer to the periodic table in the Chemistry: Problems and Solutions book for this question.
Which example is an exothermic reaction?
Answer: condensation
Question: Two objects (A and B) of the same temperature are in contact with each other.
Which statement is true?
Answer: Although the molecules collide, no heat transfers because there is no temperature difference between the objects.
Question: Which parameter is measured directly in a coffee-cup calorimeter?
Answer: temperature
Question: Which type of substance would be best for use in a heating system?
Answer: a liquid with a high specific heat
Question: The reaction 2NO(g) → N2(g) + O2(g) has a ΔH=−180.5kJ .
How much heat will be required to produce 44.8 L of NO by the reverse reaction?
Answer: 180.5 kJ
Question: Which statement is true?
Answer: In an exothermic reaction, the energy of the products is less than the energy of the reactants.
Question: Which statement is a correctly written thermochemical equation?
Answer: 4Fe(s)+3O2(g)→2Fe2O3(s), ΔH=−3,926kJ
Question: What is likely to be true about the ΔH for this reaction?
C6H6 (s) → C6H6 (l)
Answer: ∆H>0
Question: Two hundred grams of a substance requires 0.52 kJ of heat to raise its temperature from 25°C to 45°C.
Use the table to identify the substance.
q=mCΔT.
Mass (m) is in grams. Temperature is in degrees Celsius.
Picture of Graph included.
Answer: gold
Question: A chemical reaction is carried out in a closed container. The energy absorbed by the chemical reaction is 200 kJ.
What is the energy liberated from the air or the walls of the container?
Answer: 200 kJ