Calorimetry

Calorimetry

By Andrew Baldwin

Multiple Choice

What type of energy transformation occurs, when a hawk eats a mouse and then uses the energy from the mouse to fly?

• mechanical energy to chemical energy

• thermal energy to mechanical energy

• chemical energy to mechanical energy

• mechanical energy to thermal energy

Multiple Choice

A hairdryer converts -- 

• electrical energy into chemical
• electrical energy into thermal
• chemical energy into mechanical
• thermal energy into mechanical

Multiple Choice

What type of energy is stored in batteries or food?

• Potential energy

• Thermal energy

• Chemical energy

• Mechanical energy

Multiple Choice

When iron nails get rusty, heat is released.  What process is this?

• Exothermic
• Endothermic

Multiple Choice

Heat transfers from an area of ____temperature to an area of ___ temperature.

• high to low
• low to high
• high to high
• It can travel high to low and low to high. 

Multiple Choice

What would likely happen if you were to touch the flask in which an exothermic reaction was occurring?

• The flask would feel cooler

• The flask would feel warmer

• The flask would feel the same before and after a reaction

• None of the above

Multiple Choice

A student mixed two chemicals to allow them to react. The temperature before the reaction was 25 ° C. The temperature after the reaction was 18° C. Which of the following is true? 

• The temperature changed 
• It is an endothermic reaction
• It is an exothermic reaction 
• Two of the answers are correct 

Multiple Choice

If the enthalpy ter (ΔH) is negative the reaction is ____.

• Endothermic
• Exothermic
• Neutral

Multiple Choice

What is the PE of the reactants?

• 40 kJ
• 20 kJ
• 100 kJ
• 60 kJ

Multiple Choice

What is the energy of the activated complex?

• 75 kJ
• 225 kJ
• 300 kJ
• 225 kJ

Poll

Rate your Confidence

• I got this

• I understand

• It makes sense

• I am lost

Multiple Choice

If two objects have different temperatures when they come in contact, heat will flow from the warmer object to the cooler one UNTIL ____________

• one reaches a temperature of zero

• they both have an equal temperature

• one runs out of energy

Multiple Choice

What is the specific heat of an unknown substance if 100.0 g of it at 200.0 °C reaches an equilibrium temperature of 27.1 °C when it comes in contact with a calorimeter of water.  The water weighs 75. g and had an initial temperature of 20.00 °C?  (Specific heat of water is 4.18 J/g°C) (show your work)

• 0.111 J/g°C
• 1.29 J/g°C
• 0.129 J/g°C
• 22225.85 J

Multiple Choice

A sample of iron receives 50.J of heat energy that raises the temperature of the iron by 25.0°C. If the iron has a specific heat of 0.10 J/g°C, what is the mass of the iron sample?  (show your work)

• 25g
• 30g
• 20g
• 50g

Poll

Rate your confidence

• This is a cakewalk.

• That's it. Ok

• I mean, it makes sense

• Run that back one more time.