Name:______Date:______
1.2 How do you calculate heat when there is a temperature change? ADPHS Instructor Ms. Kasia Room 109
UNIT 1 ENERGY
1.2 Ice making, Water boiling, and fish in hot water
1. MAKING ICE
Name:______Date:______
1.2 How do you calculate heat when there is a temperature change? ADPHS Instructor Ms. Kasia Room 109
a. What is the temperature of the water before you place in your ice maker? (in oC) ______
Typical Temperatures
°C / °F / Description100 / 212 / Water boils
37 / 98.6 / Body temperature
21 / 70 / Room temperature
10 / 50 / Cool Day
0 / 32 / Freezing point of water
-18 / 0 / Very Cold Day
Name:______Date:______
1.2 How do you calculate heat when there is a temperature change? ADPHS Instructor Ms. Kasia Room 109
b. What is the temperature inside your freezer? (oC) ______
“Although water freezes at 32 Fahrenheit (0 Celsius) most foods require much lower temperatures to freeze.
The ideal freezer temperature is 0 Fahrenheit (-18 Celsius) for storing food. And -10 Fahrenheit (-23 Celsius) is recommended when freezing food. “
-excerpt from Ideal Freezer Temperature (http://www.favoritefreezerfoods.com/ideal-freezer-temperature.html)
c. You have 100 grams of water you want to freeze, how much heat do you need to get rid off?
d. Formula:______
2. KETTLE BOILING
Name:______Date:______
1.2 How do you calculate heat when there is a temperature change? ADPHS Instructor Ms. Kasia Room 109
a. You want to boil 2 liters of water (1mL=1g)______
b. What is the temperature of the water before you place it the kettle? (oC)______
c. What is the temperature of the water when it boils? (oC)______
Name:______Date:______
1.2 How do you calculate heat when there is a temperature change? ADPHS Instructor Ms. Kasia Room 109
d. Formula:______
3. GLOBAL WARMING
“Are we putting our fish in hot water?”—WWF Climate Change Programme
Fish are increasingly threatened by global warming. Greenhouse gases released mainly by humans burning coal, oil and natural gas have led to a sharp rise in mean global temperatures over the last 50 years. Temperatures are raising causing rivers, lakes and even oceans to heat up.
Warmer waters, as well as changes in rainfall, currents, and sea level, are already affecting the world’s fish and fisheries. While slightly warmer water may not sound so bad to many of us, its effect on fish and aquatic ecosystems, and ultimately on the global food supply and economic stability, could be severe.
Fish are more sensitive to temperature than many animals because they cannot maintain a constant body temperature like we do—in most cases their body temperature is exactly the body temperature of the water. Each species has a range of temperatures that it prefers, and fish can’t survive in temperatures too far out of this range.
As water warms up, fishes’ metabolisms speed up, making them want to eat more; this means they need more food and oxygen to survive. If there is not enough food they have less energy. Rainbow trout grow significantly more slowly when their water temperature is raised only 2oC and food is limited.
Experiments suggest that a warming of 3oC will double the food supply for arctic trout, but their metabolism will increase so much that young trout will still starve.To make matters worse, fish many not have enough oxygen to breathe as the water grows warmer. That is because the amount of oxygen dissolved in water decreases as temperature rises.
Ultimately, an increase in 1oC to 2oC could cause massive fish kills, especially in tropical aquaculture ponds or shallow spools of the Amazon River.
a. If you wanted to change the temperature of 1000 liters of water by 3oC, how much heat do you need?
b. If the ocean has a volume of 354,700,000,000,000,000,00 liters, how much heat is needed to change its temperature by 1oC?
c. You used 6000 joules to increase the temperature of your local pond. Your pond has 2000liters of water. If the initial temperature of the pond is 4oC, what is the final temperature?