Determine the heat released in the reaction if 9.78 g of rubidium hydroxide dissolved in 500.0 g of water with a temperature change of 25.0 °C to 78.0 °C.

• A. -2.77 kJ/mol
• B. - 1.18x10³ kJ/mol
• C. 2.77 kJ/mol
• D. 1.18x10³ kJ/mol

Answer: (B)