Water (2290 g ) is heated until it just begins to boil. if the water absorbs 5.57×105 j of heat in the process, what was the initial temperature of the water?

So the formula you will be needing looks like this:

Q = m * c * (T_f - T_),

where Q is the heat transferred to the water, m is the mass of the water, c is the specific heat capacity of water, and T_f and T_i are your final and initial temperatures, respectively. Now, you know that the final temperature is 100 degrees Celcius, because that is the temperature at which water boils. Rearranging the formula so that it gives you the initial temperature, you get:

T_f - Q/(m*c) = T_i

Putting in the numbers, we get:

T_i = 41.8 degrees Celcius