"A mass of 45.0g of molten silver at its melting point is poured into 750mL of calorimeter water at 25.0C. The final temperature reached by both is 30.0C. If the specific heat capacity of silver is 0.235 kJ/kgC, calculate the molar heat of solidification of silver".
Help! I don't know the process of solving this. Why are we given the specific heat capacity of silver?
heat lost by Ag turning to solid + heat lost by Ag in heating water + heat gained by water = 0
I don't think you can work this problem unless your are given the melting point of silver. You must know WHERE the initial T is. Perhaps you are to look it up. I did that on the web.
-[mass Ag x heat fusion] + [mass Ag x specific heat Ag x (Tfinal-Tinitial)] + [mass water x specific heat water x (Tfinal-Tinitial)] = 0
You are given all of the information except melting point of Ag AND heat fusion.
I don't think I need heat fusion...I'm looking for the molar heat of solidification.
But, thank you so much! I got it.
Just for your information, the heat of fusion and the heat of solidification are the same. Just like the heat of vaporization and heat of condensation are the same. The only difference is heat fusion is melting at the melting point and heat of solidification is the solidifying at the melting point. The equation I gave will solve for heat fusion in J/g.
To solve this problem, you need to understand the basic principles of heat transfer and use the equation for heat transfer, which is:
Q = mcΔT
Where:
Q = heat transfer
m = mass
c = specific heat capacity
ΔT = change in temperature
In this case, we have a mass of 45.0 g of molten silver at its melting point (which means the temperature is the same as the melting point temperature). It is poured into 750 mL of water at 25.0°C in a calorimeter. The final temperature reached by both substances is 30.0°C.
First, let's calculate the heat transfer for the silver using the equation above. However, before doing that, we need to convert the mass of silver to kilograms:
mass_silver = 45.0 g = 0.045 kg
Now, we can calculate the heat transfer for the silver:
Q_silver = (0.045 kg) * (0.235 kJ/kg°C) * (30.0°C - melting point temperature)
The melting point temperature of silver is not given in the question, so we cannot calculate Q_silver yet. However, we are given the specific heat capacity of silver, which is 0.235 kJ/kg°C.
The specific heat capacity is the amount of heat energy required to raise the temperature of 1 kg of a substance by 1 degree Celsius. It is given to you so that you can use it to calculate the heat transfer for the silver.
To determine the molar heat of solidification of silver, you will need to know the final temperature reached by both substances (30.0°C) and the melting point temperature of silver. Once you have these values, you can calculate the heat transfer for the silver using the equation above and then use the concept of molar heat to find the molar heat of solidification of silver.
Therefore, the specific heat capacity of silver is given to you as a necessary component in calculating the heat transfer for the silver in the given situation, leading to the determination of the molar heat of solidification.