In an experiment, 11.6g of a salt was dissolved in 100.0ml of water contained in the above calorimeter, all at an initial tmperature of 24.5 degrees Celsius. After dissolution was complete, the temperatur was 31.8C. The specific heat of the solution is 3.63J/gxC and the molecular mass of the salt is 153.5 g/mol. Assume there is no heat loss to the surroundings.
A) Calculate the heat gained by the soution
B) Calculate the heat gained by the calorimeter
C) Calculate the total ehat gained by the system.
D) Calculate the heat of solution (delta H)of the salt in J/mol.
Do you have a calorimeter constant listed? Or some way to calculate the constant?
The heat gained by the solution (part a) is
mass x specific heat x (Tfinal-Tinitial)
111.6 x 3.63 x (31.8-24.5) = ??
To calculate the different heat values, we can use the equation:
q = mcΔT
where:
q is the heat gained or lost
m is the mass of the substance
c is the specific heat of the substance
ΔT is the change in temperature
Before we calculate each value, let's write down the given information:
Mass of the salt (m) = 11.6g
Volume of water (V) = 100.0ml (which is equivalent to 100.0g, since the density of water is approximately 1g/ml)
Initial temperature (T1) = 24.5°C
Final temperature (T2) = 31.8°C
Specific heat of the solution (c) = 3.63J/g°C
Molecular mass of the salt = 153.5g/mol
Now, let's solve each part of the question step by step:
A) Calculate the heat gained by the solution:
q(solution) = m(solution) * c(solution) * ΔT(solution)
First, we need to calculate the mass of the solution. Since the salt was dissolved in 100.0ml of water, the mass of the solution (m(solution)) is equal to the sum of the mass of the salt (m(salt)) and the mass of water (m(water)):
m(solution) = m(salt) + m(water)
m(water) = V(water) = 100.0g (already given)
m(salt) = 11.6g (given)
m(solution) = 11.6g + 100.0g = 111.6g
Now we can calculate the heat gained by the solution:
q(solution) = 111.6g * 3.63J/g°C * (31.8°C - 24.5°C)
B) Calculate the heat gained by the calorimeter:
q(calorimeter) = m(calorimeter) * c(calorimeter) * ΔT(calorimeter)
Since the calorimeter is assumed to be the same temperature as the solution, ΔT(calorimeter) = ΔT(solution) = 31.8°C - 24.5°C
We are given the specific heat of the solution (c(calorimeter)) as 3.63J/g°C, but we don't know the mass of the calorimeter (m(calorimeter)). Without this information, we cannot calculate the heat gained by the calorimeter.
C) Calculate the total heat gained by the system:
q(total) = q(solution) + q(calorimeter)
However, since we cannot determine q(calorimeter) without the mass of the calorimeter, we cannot calculate the total heat gained by the system.
D) Calculate the heat of solution (ΔH) of the salt in J/mol:
ΔH(salt) = q(solution) / n(salt)
The heat of solution is defined as the amount of heat released or absorbed when one mole of a substance dissolves in a solvent. To calculate it, we need to know the number of moles of the salt (n(salt)).
To find n(salt), we can use the formula:
n(salt) = m(salt) / M(salt)
where:
m(salt) is the mass of the salt in grams (11.6g in this case)
M(salt) is the molar mass of the salt in grams/mol (153.5g/mol)
Now we can calculate ΔH:
ΔH(salt) = q(solution) / n(salt)
Remember to convert the mass of the salt to moles by dividing by the molar mass before calculating ΔH.