Ice-Melting Blocks

Introduction

• • Why does ice melt faster on one ice-melting block than the other?

• The "cold" block is made of aluminum, which has one of the highest heat conductivities. Like most metals, aluminum feels cold to the touch because metals are good conductors.

• The "warm" block is made of a plastic foam. Most plastics are poor conductors of heat. The low conductivity of the plastic means that it does not readily transfer the heat needed to the ice cubes in order to melt them.

Materials

• Ice-Melting blocks with O-rings

• Ice cubes

Procedure

• Get the Ice Melting Blocks product and notice that there are two identical-looking blocks.

• Touch the blocks and make note that one block feels cold and the other feels warm.

• Place one ice cube on each block and observe which ice cube melts faster.

Scientific Principle

• Melting ice is an endothermic process because it requires heat.

• The "cold" block is a heat conductor and easily transfers heat energy to the ice cubes to melt the ice.

• The "warm" block is an insulator and does not provide the heat needed to melt the ice cubes.

  • When heat is transferred to an object, the temperature of the object increases. When heat is removed from an object, the temperature of the object decreases. The relationship between the heat ( q ) that is transferred and the change in temperature ( ΔT ) is

    • q = C ΔT = C ( T_f - T_i )

Safety Regulations

• Be cautious not to drop ice on floor because it can become very slippery.