Themochemistry

Is the combustion of gasoline endothermic or exothermic?

• Endothermic
• Exothermic

For the formula:
 Q= m c ∆T
The  units for specific heat (C) are:

• g /J°C
• °C/g J
• kJ/g
• J/g°C

Using the heat equation, Q=mC∆T, what would the formula look like if we were solving for change in temperature  (i.e ∆Tis the unknown)?

• Q m=∆T c
• Q/mc= ∆T
• Qm/c=∆T
• mcQ=∆T

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

• 25g
• 30g
• 20g
• 50g

Do reactants in an endothermic reaction have a higher or lower energy than the products? 

• Higher
• Lower

What would be the effect on the particles if they were heated?

• They would slow down
• They would stop moving
• They would speed up
• There would be no effect

True or False: The ΔH value in an endothermic reaction is positive.

• True
• False

What kind of graph is this?

• endothermic
• exothermic
• both
• neither

Tags

NGSS.HS-PS1-4

A process that absorbs heat is a(n) _______________ reaction?

• polythermic
• ergothermic
• exothermic
• endothermic

žDetermine the energy (in J) required to raise the temperature of 100.0 g of water from 20.0 C to 85.0 C? The specific heat of water is 4.184 J/g°C

• 500 J
• 4,182 J
• 27,196 J
• 27200 J