When 8.00 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 77.62°C.If the specific heat of the solution is 4.18 J/(g ∙ °C),calculate ΔH for the reaction,as written. Ba(s)+ 2 H₂O(l)→ Ba(OH)₂(aq)+ H₂(g)ΔH = ?

Question

Quizplus · Accepted Answer

First, we need to use the equation q = m*c*ΔT to calculate the heat absorbed by the solution:
q = 100.00 g * 4.18 J/(g * °C) * (77.62°C - 22.00°C) = 191772 J

Since the reaction is exothermic, the heat absorbed by the solution is equal to the heat released by the reaction:
q = -ΔH

Therefore, ΔH = -191772 J. Converting this to kJ and keeping the negative sign because the reaction is exothermic, we get:

ΔH = -191.8 kJ

Rounding this to the nearest whole number and changing the sign, we get:

ΔH = -192 kJ

The closest answer choice to this value is A, -431 kJ. Therefore, the best choice is A.

When 800 G of Ba(s)is Added to 100