When 3.926g of NaOH is added to 100.0mL of water, the temperature of the solution increases by 28 degrees Celsius. Assume the density of the solution to be 1g/mL and specific heat capacity of the solution to be 4.184 J/gK. I'm unsure of which formula to use. I was going to use q=(m)(Cs)(T) but I don't know the initial or final temperature.

You don't ask the question but I assume you will be calculate delta H or something like that. Yes, use q = mcdT. That's right, you don't have Tfinal and Tinitial BUT the problem tells you T increased by 28 C so Tfinal-Tinitial = 28

I apologize for my typo, I meant to write that the temperature increased by 2.8 degrees. Does that change anything or should I still just plug that into the formula?

Plug and chug.delta T is 2.8

Thank you!

To find the correct formula to use in this scenario, let's analyze the given information.

We know that 3.926g of NaOH is added to 100.0mL of water, resulting in a temperature increase of 28 degrees Celsius. From this, it is clear that we are dealing with a heat transfer scenario.

The heat transferred can be calculated using the formula:

q = m * Cs * ΔT

Where:
q is the heat transferred (in joules)
m is the mass of the solution (in grams)
Cs is the specific heat capacity of the solution (in J/gK)
ΔT is the change in temperature (in degrees Celsius)

Although you mentioned that you don't know the initial or final temperature, the change in temperature, ΔT, is given as 28 degrees Celsius. This allows us to use the formula since we do not need the individual initial and final temperatures.

In this case, the mass of the solution, m, can be calculated by considering the density of the solution. You are given that the density of the solution is 1g/mL. Since the volume of the solution is given as 100.0mL, the mass of the solution can be calculated by multiplying the volume by the density:

m = V * density

m = 100.0mL * 1g/mL

m = 100.0g

Now that you have the mass of the solution (m) and the change in temperature (ΔT), you can substitute these values into the formula:

q = (m)(Cs)(ΔT)

q = (100.0g)(4.184 J/gK)(28°C)

By performing the calculations, you can find the heat transferred (q) in joules.