a coffee cup calorimeter normally consists of two nested styrofoam cups with a lid. a coffee cup calorimeter of this type contains 125.0 g of water at 20.00 degrees C. A 120.0 g sample of copper metal is heated to 98.0 degrees C by putting it into a beaker of hot water. The copper is then put into the calorimeter and the final temperature of the water and copper is 25.80 degree C
calculate the energy change of the copper metal?
heat lost by Cu = heat gained by H2O.
q = heat gained by water = mass H2O x specific heat H2O x (Tfinal-Tinitial).
OR, heat lost by Cu is
mass Cu x specific heat Cu x (Tfinal-Tinitial)
still don't get it
q= 20.00 C =125.0g x 98.0 C x 25.80 C -20.00??
Well, it's a funny question, at least in the wording. Questions of this type USUALLY ask for the final T or give the final T and ask for the initial T. Still others give both final T and initial T and ask for specific heat or the mass of the metal or the mass of water. In this case, however, the problem give mass, I assume they intend you to look up the specific heats (of Cu or H2O) and it gives final T and initial T. It asks for energy (which I translate as heat)
"Still don't get it" isn't very helpful. you need to tell us what you problem is. My first response gives you my rationale and I see no point in repeating what I wrote above. The numbers are not what you have placed in what appears to be a random order.
q = heat lost by copper = energy lost by copper = mass copper x specific heat copper x (Tfinal-Tinitial).
mass copper = 120.0 g
specific heat copper--That isn't given in the problem. I assume you are look it up in tables in your text and/or notes.
Tfinal = 25.80 C
Tinitial = 98.0
Solve for q.
To calculate the energy change of the copper metal using a coffee cup calorimeter, you can use the principle of energy conservation. The heat lost by the copper metal is equal to the heat gained by the water in the calorimeter.
To find the heat gained by the water, you can use the equation:
q = m * c * ΔT
where:
q is the heat gained or lost (in joules),
m is the mass of the water (in grams),
c is the specific heat capacity of water (4.184 J/g°C), and
ΔT is the change in temperature of the water (in °C).
Given data:
Mass of water (m) = 125.0 g
Initial temperature of water = 20.00 °C
Final temperature of water and copper = 25.80 °C
Calculating the ΔT:
ΔT = Final temperature - Initial temperature
ΔT = 25.80 °C - 20.00 °C
ΔT = 5.80 °C
Calculating the heat gained by the water:
q (water) = m * c * ΔT
q (water) = 125.0 g * 4.184 J/g°C * 5.80 °C
q (water) ≈ 30793 J
Next, you need to find the energy change of the copper metal. Since there is no change in the temperature of the copper, we can assume that the heat gained by the water is equal to the heat lost by the copper:
q (copper) = -q (water)
q (copper) ≈ -30793 J
The negative sign indicates that the copper released heat to the water.
Therefore, the energy change of the copper metal is approximately -30793 J (joules).