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),calculate for the reaction,as written. Ba(s)+ 2 H₂O(l)→ Ba(OH)₂(aq)+ H₂(g) = ?

Question

Quizplus · Accepted Answer

First, we need to calculate the heat absorbed by the solution using the equation:

q(solution) = m(solution) x Cs x ΔT

where q(solution) is the heat absorbed by the solution, m(solution) is the mass of the solution (100.00 g), Cs is the specific heat of the solution (4.18 J/(g ∙ °C)), and ΔT is the change in temperature (33.10°C - 22.00°C = 11.10°C).

q(solution) = (100.00 g) x (4.18 J/(g ∙ °C)) x (11.10°C)
q(solution) = 4643.8 J or 4.64 kJ

Next, we need to calculate the moles of Ba used in the reaction using its molar mass:

molar mass Ba = 137.33 g/mol
moles Ba = mass Ba / molar mass Ba
moles Ba = 1.50 g / 137.33 g/mol
moles Ba = 0.01093 mol

Finally, we can use the heat absorbed by the solution and the moles of Ba used in the reaction to calculate the enthalpy change for the reaction using the equation:

11ea6923_17ed_49a1_80d0_8d8fb31a55fb_TB6105_11 = q(solution) / moles Ba

11ea6923_17ed_49a1_80d0_8d8fb31a55fb_TB6105_11 = (4.64 kJ) / (0.01093 mol)
11ea6923_17ed_49a1_80d0_8d8fb31a55fb_TB6105_11 = -423.93 kJ/mol

The negative sign indicates that the reaction is exothermic, meaning it releases heat to the surroundings. Therefore, the best choice is A) -431 kJ.

When 150 G of Ba(s)is Added to 100