Phase Change

Frozen Fire

Andit MacarineEchin PalomaAndaluz Yamilo

Bonono RuperezCabag Lagura

Sulapas Espinosa Lumogdang

Introduction

Another change that may occur when heat is added to or taken out from an object is phase change. For example, you know that water can change from solid (ice) to liquid (water) or from liquid to gas (steam).

Materials

Crushed Ice Glass container/beaker Timer Stirring rod Thermometer Electric Burner Wire gauze Weighing scale

Procedures

Weigh the ice/ice cubes. Record its mass as m1.

Mass of ice (m1): 423 g Measure the temperature of the ice and

assign it as the initial temperature T1. Temperature (T1): 0 degree Celsius. Stir the contents of the container, then

measure the temperature of the contents every 2 minutes after all the ice has completely melted. Record the temperature in Table 1.

Table 1. Temperature readings for melting ice

Time (min) Temperature (degree Celsius)

2 1 degree Celcius

4 1 degree Celcius

6 3 degrees Celcius

8 4 degrees Celsius

10 4 degrees Celsius

12 6 degrees Celsius

14 5 degrees Celsius

16 4 degrees Celsius

18 8 degrees Celsius

Weigh the liquid contents of the beaker and record its mass as m2 and its temperature as T2.

M2 = 295 g

T2 = 7 degrees Celsius

Continue taking the temperature of the liquid water until the temperature starts to increase.Record the time it takes for the liquid water to increase its temperature from T2.

Time taken for the temperature to start rising from T2:

1 minute

Heat the contents of the beaker. Get the temperature reading every 2 minutes until the water boils and record it in Table 2.

Table 2. Temperature reading of boiling water

Time (min) Temperature(degrees Celsius)

2 29 degrees Celsius

4 38 degrees Celsius

6 46 degrees Celsius

8 55 degrees Celsius

10 68 degrees Celsius

12 77 degrees Celsius

14 85 degrees Celsius

16 93 degrees Celsius

18 99 degrees Celsius

Continue boiling for the next 3-5 minutes and record the temperature as T3.

T3 = 99 degrees Celsius

Questions

What heppens to the temperature of water while changing from ice to liquid to water?

The temperature increases. Why does ice inside the container melt

after some time?Because of the factors that affects

the melting of the ice, like the stirring that produces friction and gives off heat which makes melting possible and much faster.

Construct a Temperature vs. Time graph for Tables 1 and 2.

What similarities and differences have you noticed between your graphs for table 1 and

table 2?

Similarities Differences

The data in boh table were increasing.

The table 1 consists of lower temperature and the gap of datas in table 1 were small.

While in table 2, there is a big gap of datas or higher increase of temperature.

How much heat was used to change the ice to steam?

Qtotal = mcice (Tm-Ti) + mHf + mcwater (Tv-Tm) + mHv + mcsteam (Tf-Tv)

= 0.423 kg (0.5 kcal/kg degree Celsius) (0 degree Celsius – 1 degree Celsius) + 0.423 kg (80 kcal/kg) + 0.295 kg ( 1 kcal/kg degree Celsius) (100 dgrees Celsius – 0 degree Celsius) + 0.295 kg (0.48 kcal/kg) (99 degrees Celsius – 100 degrees Celsius)

= 63.27 kcal

Generalization

An ice cube placed in a container and settled in expected to meet and when it was stirred the faster is the melting process. As the ice turns into liquid, the temperature was observed to increase. Healing the melted ice using the burner affects the temperature and evaporation occurs then.

Pictures