Suppose that 50.0 mL of a 0.250 M HCl solution is mixed with 50.0 mL of a 0.100 M
Ba(OH)2 solution in a coffee-cup calorimeter. The temperature of the resulting solution increases by
1.76 oC . Calculate DH for the reaction between HCl (aq) and Ba(OH)2 (aq) in kJ per mole of Ba(OH)2 reacted. Assume that the specific heat capacity of the resulting solution is 4.18 J/g oC and
that the density of the resulting solution is 1.00 g/mL . Also assume that the heat capacity of the
calorimeter itself can be ignored.
![DrBob222](/images/users/0/1/128x128.jpeg)
9 years ago
![DrBob222](/images/users/0/1/128x128.jpeg)
9 years ago
q = [mass H2O x specific heat H2O x delta T]
Then dH is q/mol Ba(OH)2 and convert to kJ.
![y](/images/users/0/1/128x128.jpeg)
6 years ago
175j
![Explain Bot](/images/users/4931/128x128.jpeg)
7 months ago
To calculate ΔH for the reaction between HCl and Ba(OH)2, we can use the equation:
ΔH = q / n
where ΔH is the enthalpy change, q is the heat transferred during the reaction, and n is the number of moles of Ba(OH)2 reacted.
First, let's calculate the amount in moles of Ba(OH)2 reacted:
n = C * V
where n is the number of moles, C is the concentration in moles per liter (M), and V is the volume in liters.
For Ba(OH)2 solution:
C = 0.100 M
V = 50.0 mL = 0.0500 L
n = (0.100 M) * (0.0500 L) = 0.00500 moles
Next, we need to calculate the heat transferred during the reaction (q). We can use the formula:
q = mcΔT
where q is the heat transferred, m is the mass of the resulting solution, c is the specific heat capacity of the solution, and ΔT is the change in temperature.
First, let's calculate the mass of the resulting solution:
mass = density * volume
mass = (1.00 g/mL) * (50.0 mL + 50.0 mL) = 100.0 g
Now let's calculate the heat transferred:
q = (100.0 g) * (4.18 J/g oC) * (1.76 oC) = 736.08 J
Finally, let's calculate ΔH:
ΔH = q / n
ΔH = (736.08 J) / (0.00500 mol) = 147,216 J/mol
To convert J to kJ, divide by 1000:
ΔH = 147,216 J/mol / 1000 = 147.22 kJ/mol
Therefore, the ΔH for the reaction between HCl and Ba(OH)2 is 147.22 kJ/mol of Ba(OH)2 reacted.