Chemistry 11th Ch 7-11

Heat flows from _______ to ______ objects

• cooler to warmer
• warmer to warmer
• warmer to cooler
• cooler to cooler

Energy can not be created or destroyed, it can only be transferred refers to the....

• law of conservation of energy
• law of conservation of mass
• life facts
• law of conservation of chemistry

Heat travels from the sun to the earth by the process of...

• conduction
• convection
• radiation
• insulation

Which of the following is an example of an endothermic process or reaction?

• condensing

• freezing

• combustion

• melting

Which of the following is an example of an exothermic process or reaction?

• melting

• boiling

• photosynthesis

• freezing

.

How does an exothermic reaction compare with an endothermic reaction?

• Both changes absorb energy as reactants become products.

• Both changes release energy as reactants become products.

• An exothermic reaction absorbs energy, and an endothermic reaction releases energy.

• An endothermic reaction absorbs energy, and an exothermic reaction releases energy.

The symbol for specific heat is .......

• c
• Q
• m
• t

What  is the formula to calculate heat energy required to raise the temperature of any substance?

• Q=mc∆t
• Q=mc
• Q= ½mv
• m=QC

The specific heat of platinum is 0.133 J/g°C. How much heat(Q) is released when a 10 g piece of platinum cools from 100°C to 50°C?

• 66.5 J

• 665 J

• 0.0266 J

• 0.665 J

The temperature of an unknown piece of metal with a mass of 30.00 g changes from 25.0 °C to 35.0 °C when the metal absorbs 350.0 J of energy. What is the specific heat of the metal?

• 1.17 J/g°C
• -1.17 J/g°C
• 0.857 J/g°C
• -0.857 J/g°C