When 1.50 g of Ba(s) is added to 100.00 g of water in a container open to the atmosphere, the reaction shown below occurs and the temperature of the resulting solution rises from 22.00°C to 33.10°C. If the specific heat of the solution is 4.18 J/(g °C), what is the heat absorbed by the solution?

• A. 4620 J
• B. 5200 J
• C. 4000 J
• D. 3500 J

Answer: (A)

Verified step by step guidance

1. Identify the chemical reaction: Ba(s) + 2H₂O(l) → Ba(OH)₂(aq) + H₂(g). This reaction releases heat, causing the temperature of the solution to rise.
2. Determine the mass of the solution. Since the mass of water is 100.00 g and the mass of Ba is 1.50 g, the total mass of the solution is 101.50 g.
3. Calculate the change in temperature (ΔT) of the solution. ΔT = final temperature - initial temperature = 33.10°C - 22.00°C.
4. Use the formula for heat absorbed or released: q = m × c × ΔT, where q is the heat absorbed, m is the mass of the solution, c is the specific heat capacity, and ΔT is the change in temperature.
5. Substitute the known values into the formula: m = 101.50 g, c = 4.18 J/(g °C), and ΔT = (33.10 - 22.00) °C. Calculate q to find the heat absorbed by the solution.