I need help!

I found the change in Temp= -.9 degree C. I don't know what to do next...?

What value from this problem do I use as my q(heat capacity) to plug into the equation q= m X Cs X change T?

The question states:
120mL of H2O is intially @ room temp (22 degree C). A chilled steep rod @ 2 degree C is placed in the water. If the final temp of the system is 21.1 degree C, what is the mass of the rod?

Thank You!!!

The rod is cooler than the water; therefore, the rod will gain heat and the water will lose heat and the two added together will be zero (one will be negative).

massrod x specific heat rod x (Tfinal-Tinitial) + massH2O x specific heat water x (Tfinal-Tinitial) = 0
Solve for
You will need to look up the specific heat of the rod and the water if they are not listed in the problem. Post your work if you get stuck.

I did not get the correct answer...

Solve for MassSteel.
Here is my work-

masssteelx specific heat rod x (Tfinal-Tinitial) + massH2O x specific heat water x (Tfinal-Tinitial) = 0

MassSteel = -massH2O x specific heat water x (Tfinal-Tinitial)/ specific heat rod x (Tfinal-Tinitial)

MassSteel = -120mL x 4.18J/gC x -1C/ 0.452 J/gC x -1C

MassSteel = 1109.73

What did I do wrong???

I think trying to shuffle the equation with algebra makes the problem harder. I think what you did wrong is that you didn't substitute Tf-Ti correctly.

Here is what I did:
massrod x sp.h.rod x (Tf-Ti) + massH2O x sph.H2O x (Tf-Ti) = 0
mass rod = Y
[Y*0.452*(21.1-2)] + [120*4.18*(21.1-22.0)] = 0
8.633Y-451.44 = 0
PLEASE check what I've done to make sure I've not made an error. You can finish the problem but the answer I obtained is approximately 50 g. It appears to me that you substituted 1 for Tf-Ti for both rod and water. I hope this helps. Let me know if you have any problems.

It worked!! Thanks so much for your help!

To solve for the mass of the rod, you need to use the equation q = m * Cs * ΔT, where q is the heat transfer, m is the mass, Cs is the specific heat capacity of the substance, and ΔT is the change in temperature.

In this case, you have the change in temperature, which is -0.9°C, and you need to find the mass of the rod.

To use the equation, you first need to determine the specific heat capacity of water (Cs). The specific heat capacity of water is 4.18 J/g°C.

To find the heat transfer, you can rearrange the equation as follows:

q = m * Cs * ΔT

Since the temperature change in this case is given in degrees Celsius, you can rearrange the equation as:

q = m * Cs * ΔT
-0.9°C = m * 4.18 J/g°C * (-0.9°C)

By plugging in the values, you can solve for the mass of the rod:

-0.9°C = m * 4.18 J/g°C * (-0.9°C)

Now, divide both sides of the equation by 4.18 J/g°C * (-0.9°C) to isolate the mass:

m = -0.9°C / (4.18 J/g°C * (-0.9°C))

Simplifying further will give you the mass of the rod.

I hope this helps! Let me know if you have any further questions.