Answer:
The correct answer is 281.39 grams.
Explanation:
To arrive at this answer you must first keep in mind the basic equation:
<em>Q = m*Cp* ΔT</em>
Now, in order to calculate the necessary aluminum mass that absorbs 2138 J when passing from 14.83 to 23.31 ° C you must "clear" <em>m</em> of the previous equation.
This means, leave only the mass on one side of the equation, and "pass" <em>Cp</em> and <em>ΔT</em> to the other side dividing <em>Q</em>. This would look like this:
m= Q/ (Cp*ΔT)
Then, <u>you need the value of specific heat of aluminum</u> in the correct units, that is J / g ° C, the approximate value is 0.896.
ΔT is calculated by doing the mathematical operation:
23.31 °C - 14.83 °C = 8.48 °C
<em>
Finally, the values of: Q (data provided in joules), Cp (J / g ° C) and ΔT (calculated in ° C) are replaced in the last equation and the mass (in grams) is calculated resulting in 281.39 grams.</em>