In a constant-pressure calorimeter, 50.0 mL of 0.300 M Ba(OH)2 was added to 50.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 24.50 degrees C to 28.59 degrees C. If the solution has the same density and specific heat as water, what is delta H for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes. Delta H = ___ kJ/mol H2O
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)
q/0.03 mol = J/mol and divide by 1000 to convert to kJ.
Ba(OH)2 + 2HCl ==> BaCl2 + 2H2O
0.015mol...0.03......0.015..0.03 mol
wait i got (18g)(4.18J)(28.59-24.50) which brings me to 307.7316, is that right? is that when i divide by 0.03? and then divide by 1000? that brought me to 10.257 is this correct..?
I got it thanks!
DrBob222 you are very unclear.... why did you do all that?
where did 0.03moles come from
IS this right?
To calculate delta H for this reaction, we can use the equation:
delta H = q / n
Where:
- delta H represents the change in enthalpy (in kilojoules per mole)
- q represents the heat absorbed or released by the reaction (in joules)
- n represents the amount of substance for which delta H is calculated (in moles)
To determine the heat absorbed or released by the reaction (q), we can use the equation:
q = m * c * delta T
Where:
- q represents the heat absorbed or released by the reaction (in joules)
- m represents the mass of the solution (in grams)
- c represents the specific heat capacity of water (4.18 J/g°C)
- delta T represents the change in temperature of the solution (in °C)
First, let's calculate the mass of the solution. Since we have the same volume for both solutions and they have the same density as water, we can assume their masses are the same.
Mass of the solution = volume of the solution * density of water
= (50.0 mL + 50.0 mL) * density of water
= 100.0 mL * density of water
Next, let's calculate the heat absorbed or released by the reaction (q).
q = mass of the solution * specific heat capacity of water * delta T
Since q is currently in joules, we can convert it to kilojoules by dividing by 1000.
Finally, we can plug the value of q into the equation for delta H to find the answer.
delta H = q / n
Since delta H is given per mole of H2O produced, n is equal to the moles of H2O produced in the reaction. We can determine this by stoichiometry, using the balanced equation for the reaction:
Ba(OH)2 + 2HCl -> BaCl2 + 2H2O
From the balanced equation, we can see that for every mole of Ba(OH)2, 2 moles of H2O are produced.
Now we have all the information we need to solve for delta H: the mass of the solution (which we calculated), the specific heat capacity of water, the change in temperature of the solution, and the moles of H2O produced.
Using this information, you can perform the calculations to find the value of delta H in kJ/mol H2O produced.