find the heat energy needed to change 150g of ice at -15c to ice at -63c
q = mass ice x specific heat ice x (Tfinal-initial)
15048
To find the heat energy needed to change 150g of ice from -15°C to -63°C, we need to consider two separate processes: First, the heat energy required to cool the ice from -15°C to 0°C, and second, the heat energy required to freeze the water from 0°C to -63°C.
1. Heat energy to cool the ice from -15°C to 0°C:
The heat energy required for this process can be calculated using the formula:
Q = m * C * ΔT
Where:
Q = heat energy
m = mass of ice
C = specific heat capacity (for ice, it is approximately 2.09 J/g°C)
ΔT = change in temperature
Let's calculate:
Q1 = 150g * 2.09 J/g°C * (0°C - (-15°C))
Q1 = 150g * 2.09 J/g°C * 15°C
Q1 = 469.5 J
Therefore, the heat energy required to cool the ice from -15°C to 0°C is 469.5 J.
2. Heat energy to freeze the water from 0°C to -63°C:
To calculate the heat energy required to freeze the water, we use the formula:
Q = m * ΔHf
Where:
Q = heat energy
m = mass of water
ΔHf = heat of fusion (for water, it is 334 J/g)
We need to convert the mass of ice to the mass of water since the water will be freezing:
150g of ice = 150g of water
Let's calculate:
Q2 = 150g * 334 J/g
Q2 = 50,100 J
Therefore, the heat energy required to freeze the water from 0°C to -63°C is 50,100 J.
The total heat energy required is the sum of Q1 and Q2:
Total heat energy = Q1 + Q2
Total heat energy = 469.5 J + 50,100 J
Total heat energy = 50,569.5 J
Therefore, the heat energy needed to change 150g of ice at -15°C to ice at -63°C is approximately 50,569.5 J.
To find the heat energy needed to change the temperature of a substance, you can use the formula:
Q = mcΔT
Where:
Q is the heat energy (in Joules)
m is the mass of the substance (in grams)
c is the specific heat capacity of the substance (in J/g°C)
ΔT is the change in temperature (in °C)
In this case, you want to find the heat energy needed to change the temperature of 150g of ice from -15°C to -63°C.
Step 1: Determine the specific heat capacity of ice
The specific heat capacity of ice is approximately 2.09 J/g°C.
Step 2: Calculate the change in temperature
ΔT = (-63°C) - (-15°C) = -63°C + 15°C = -78°C
Step 3: Substitute the values into the formula
Q = (150g) * (2.09 J/g°C) * (-78°C)
Multiplying these values will give you the amount of heat energy needed to change the temperature of the ice.