When 50.0mL of 1.20 M of HCl (aq)is combined with 50.0mL of 1.30 M of NaOH (aq) in a coffee-cup calorimeter, the temperature of the solution increases by 8.01 Degrees C. What is the change in enthalpy for this balanced reaction?
HCl(aq) + NaOH(aq) --yields-- NaCl(aq) + H20(l)
Assume that the solution density is 1.00 g/mL and the specific heat capacity of the solution is 4.18 J/ g x Degrees C
it's because the reaction is exothermic reaction so the answer should be negative, because in exothermic reaction the heat is released to the surrounding
q = [mass H2O x specific heat H2O x (Tfinal-Tinitial)
Solve for q = delta H in joules.
Then delta H/0.06 mol = delta H in J/mol. Most of these are given in kJ/mol; I recommend you convert to kJ/mol.
Well, it seems like you're looking for the change in enthalpy for this reaction. To solve this, we need to use the equation:
q = mcΔT
where q is the heat absorbed or released by the solution, m is the mass of the solution, c is the specific heat capacity, and ΔT is the change in temperature.
First, let's calculate the mass of the solution. Since the density of the solution is 1.00 g/mL, and we have a total volume of 100 mL (50 mL of each solution), the mass of the solution would be:
mass = volume x density
mass = 100 mL x 1.00 g/mL
mass = 100 g
Now, let's calculate the heat absorbed or released by the solution, q. We can use the equation:
q = mcΔT
q = 100 g x 4.18 J/g x °C x 8.01 °C
q = 3356.18 J
Now, since this reaction is exothermic (it releases heat), the heat absorbed by the solution is equal to the heat released by the reaction. Therefore, the change in enthalpy (ΔH) for this reaction is -3356.18 J.
But hey, just remember that I'm a clown bot, not a scientist, so take my answer with a pinch of clownish humor!
To determine the change in enthalpy (ΔH) for the given reaction, you can use the equation:
ΔH = q / n
Where:
ΔH = change in enthalpy (J/mol)
q = heat absorbed or released (J)
n = number of moles
To calculate the heat (q), you can use the equation:
q = m × c × ΔT
Where:
q = heat (J)
m = mass of the solution (g)
c = specific heat capacity of the solution (J/g × °C)
ΔT = change in temperature (°C)
First, let's calculate the mass of the solution. Since we have 50.0 mL of each solution, the total volume is 100.0 mL (50.0 mL + 50.0 mL). Since the density is given as 1.00 g/mL, the mass will be 100.0 g.
Next, we need to calculate the change in temperature (ΔT). The question states that the temperature of the solution increased by 8.01 °C.
Now, we can calculate the heat (q):
q = m × c × ΔT
q = 100.0 g × 4.18 J/g × °C × 8.01 °C
q = 3349.58 J
To determine the number of moles for the reaction (n), we should consider the balanced chemical equation:
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
From the equation, we can see that the ratio of HCl to NaOH is 1:1. Therefore, the number of moles of HCl is equal to the number of moles of NaOH.
To calculate the number of moles, we'll use the equation:
moles = concentration (M) × volume (L)
For HCl:
moles of HCl = 1.20 M × 0.050 L
moles of HCl = 0.060 mol
Similarly, for NaOH:
moles of NaOH = 1.30 M × 0.050 L
moles of NaOH = 0.065 mol
Since the reaction is a 1:1 ratio between HCl and NaOH, the number of moles for the reaction is 0.060 mol.
Now, we can calculate the change in enthalpy (ΔH):
ΔH = q / n
ΔH = 3349.58 J / 0.060 mol
ΔH ≈ 55826.33 J/mol
since q= 100 mL x 4.18 x 8.01
=3348.18/.06= 55803. J
to kJ= 55.803 should be the final answer, right? Because the answer key on my quiz says it's -55.8 kJ. I'm so confused because I thought for sure it would positive, especially since in the equation it says increases by 8.01, meaning it would be endothermic (+)? Am I missing something here?