The heating graph for H2O is a plot of the temperature versus the amount of heat added or removed, as H2O undergoes phase changes and changes in temperature. It is also known as the heating curve of H2O.
Here is a rough sketch of the heating graph for H2O:
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Q
In this graph, the x-axis represents the quantity of heat added or removed (Q), and the y-axis represents the temperature (T). The graph consists of three main regions:
1. Solid region: H2O is in the solid phase, and its temperature is below the melting point (0°C). During this region, the heat added to the H2O is used to increase its temperature, and the slope of the graph is positive but less steep than the liquid region.
2. Melting region: H2O is in the process of melting, and its temperature remains constant at 0°C. During this region, the heat added to the H2O is used to break the intermolecular bonds between the H2O molecules, and the slope of the graph is zero.
3. Liquid region: H2O is in the liquid phase, and its temperature is above the melting point (0°C). During this region, the heat added to the H2O is used to increase its temperature, and the slope of the graph is positive but steeper than the solid region.
To determine the quantity of energy transfer required to heat 1.0g solid H2O from -50°C to the melting point 0°C, we need to calculate the heat required to raise the temperature of the H2O from -50°C to 0°C and the heat required to melt the H2O at 0°C. We can use the following equations:
For the solid region:
Q1 = m * Cp * ΔT
Where Q1 is the heat required, m is the mass of the H2O (1.0g), Cp is the specific heat capacity of ice (2.09 J/g°C), and ΔT is the change in temperature (0°C - (-50°C) = 50°C).
Q1 = 1.0g * 2.09 J/g°C * 50°C = 104.5 J
For the melting region:
Q2 = m * ΔHfus
Where Q2 is the heat required, m is the mass of the H2O (1.0g), and ΔHfus is the enthalpy of fusion of ice (6.01 kJ/mol or 333.6 J/g).
Q2 = 1.0g * 333.6 J/g = 333.6 J
Therefore, the total heat required to heat 1.0g of solid H2O from -50°C to the melting point 0°C is:
Qtotal = Q1 + Q2 = 104.5 J + 333.6 J = 438.1 J
So, 438.1 J of energy transfer is required to heat 1.0g solid H2O from -50°C to the melting point 0°C.