To calculate the final temperature, we can use the formula:Q_lost = Q_gainedwhere Q is the heat energy, and the heat lost by the aluminum will be equal to the heat gained by the water.For aluminum, the heat lost can be calculated using the formula:Q_Al = m_Al c_Al T_initial_Al - T_final where m_Al is the mass of aluminum 25 g , c_Al is the specific heat capacity of aluminum 0.90 J/gC , T_initial_Al is the initial temperature of aluminum 80C , and T_final is the final temperature.For water, the heat gained can be calculated using the formula:Q_water = m_water c_water T_final - T_initial_water where m_water is the mass of water 100 g , c_water is the specific heat capacity of water 4.18 J/gC , T_initial_water is the initial temperature of water 25C , and T_final is the final temperature.Now, we can set the heat lost by aluminum equal to the heat gained by water:m_Al c_Al T_initial_Al - T_final = m_water c_water T_final - T_initial_water Plugging in the values:25 g 0.90 J/gC 80C - T_final = 100 g 4.18 J/gC T_final - 25C Solving for T_final:22.5 80 - T_final = 418 T_final - 25 1800 - 22.5 T_final = 418 T_final - 104501800 + 10450 = 22.5 T_final + 418 T_final11250 = 440.5 T_finalT_final = 11250 / 440.5T_final 25.54CSo, the final temperature when 25 grams of aluminum at 80C is placed in 100 grams of water at 25C is approximately 25.54C.