Question

 what mass of water can be heated from 25°c to 50°c by the addition of 2825 j of heat

Answer 1

$T_1 = 25 \;°C \\ T_2 = 50 \;°C \\ Q = 2825 \;J \\ Q = mcΔT \\ c=4.186 \;J/g°C \\ m = \frac{Q}{cΔT} \\ m = \frac{2825}{4.186(50-25)} = 26.99 \;g$

Answer: 26.99 g