A) a 100 gram ice cube is at -10 degrees celcius. how many calories needed to raise it to 0 degrees C.?
B) once its at 0 degrees, how many more calories are needed to melt it?
C) once melted, how many are needed to raise it to 100 degrees C.?
need answers t all!! thank you!!
(A) Multiply the specific heat of ice by the 100 g mass and 10 C (temperature rise).
(B) Multiply the 100 g mass by the heat of fusion. The temperature remains 0 C while ot melts.
(C) Multiply the specific heat of water by 100 g and 100 C.
If you do not know the specific heats of ice and liquid water, nor the heat of fusion, this would be a very good time to look them up.
does that mean
A= 500 cal/g.
B=8,000
C=10,000
?
To answer all three questions, we need to understand the concepts of specific heat capacity and latent heat of fusion. Specific heat capacity is the amount of heat energy required to raise the temperature of a substance by 1 degree Celsius per unit mass, and latent heat of fusion is the amount of heat energy required to change a substance from its solid state to its liquid state without changing its temperature.
A) To calculate the number of calories needed to raise a 100-gram ice cube from -10 degrees Celsius to 0 degrees Celsius, we need to know the specific heat capacity of ice. The specific heat capacity of ice is approximately 0.5 calories per gram per degree Celsius.
So, to raise the temperature of the ice cube by 10 degrees Celsius (from -10 to 0), we can use the formula:
Heat energy (in calories) = mass (in grams) x specific heat capacity (in calories/gram/degree Celsius) x change in temperature (in degrees Celsius)
Heat energy = 100 g x 0.5 calories/g/°C x 10 °C
Therefore, 500 calories are needed to raise the ice cube from -10 degrees Celsius to 0 degrees Celsius.
B) Once the ice cube reaches 0 degrees Celsius, we need to melt it. To calculate the number of calories needed to melt the ice cube, we need to know the latent heat of fusion of ice. The latent heat of fusion of ice is approximately 79.7 calories per gram.
So, the heat energy required to melt the ice is given by:
Heat energy (in calories) = mass (in grams) x latent heat of fusion (in calories/gram)
Heat energy = 100 g x 79.7 calories/g
Therefore, 7,970 calories are needed to melt the ice cube.
C) Once the ice cube is completely melted, we need to calculate the number of calories needed to raise the water to 100 degrees Celsius. The specific heat capacity of liquid water is approximately 1 calorie per gram per degree Celsius.
So, to raise the temperature of the water by 100 degrees Celsius, we can use the formula again:
Heat energy (in calories) = mass (in grams) x specific heat capacity (in calories/gram/degree Celsius) x change in temperature (in degrees Celsius)
Heat energy = 100 g x 1 calorie/g/°C x 100 °C
Therefore, 10,000 calories are needed to raise the melted ice to 100 degrees Celsius.
To summarize:
A) 500 calories are needed to raise the ice cube from -10 degrees Celsius to 0 degrees Celsius.
B) 7,970 calories are needed to melt the ice cube once it reaches 0 degrees Celsius.
C) 10,000 calories are needed to raise the melted ice to 100 degrees Celsius.