When 0.949 g of CaO is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 389C is observed.

Assume the solution's final volume is 200.0 mL, the density is 1.00 g/mL, and the heat capacity is 4.184 J/gC.

what is molar heat of reaction, Hrxn, for the reaction of

CaO(s) + 2H+(aq) = Ca2+(aq) + H2O(l) in kj/mol

Can this be right? Water boils at 100 C so how can the temperature increase by 389 degrees? That would have boiled all of the water away.

mass water x specific heat water x delta T = q
That will be q/0.949 g CaO. Convert that to moles CaO.

this is what i did: q=200x389x4.184

then q/0.949g x56.08g/1mol

but i still got the wrong answer

q/ (0.949 g / 56.08 gmol^-1)

To find the molar heat of reaction (ΔHrxn) for the given reaction, we need to use the equation:

ΔHrxn = q / n

Where:
- ΔHrxn is the molar heat of reaction in kJ/mol.
- q is the heat absorbed or released during the reaction.
- n is the number of moles of the limiting reactant.

First, let's find the number of moles of CaO (the limiting reactant) used in the reaction. We have the mass of CaO as 0.949 g. To find the moles, we divide the mass by the molar mass of CaO.

The molar mass of CaO is the sum of the atomic masses of calcium (Ca) and oxygen (O):
Molar mass of Ca = 40.08 g/mol
Molar mass of O = 16.00 g/mol

Molar mass of CaO = 40.08 g/mol + 16.00 g/mol = 56.08 g/mol

Now, calculate the number of moles of CaO:
moles of CaO = mass of CaO / molar mass of CaO
moles of CaO = 0.949 g / 56.08 g/mol

Next, we need to calculate the heat (q) absorbed or released during the reaction. To do this, we'll use the equation:

q = m * c * ΔT

Where:
- q is the heat absorbed or released in Joules (J).
- m is the mass of the solution in grams.
- c is the heat capacity of the solution in J/g°C.
- ΔT is the temperature change in degrees Celsius (°C).

We're given that the temperature change (ΔT) is 389°C, the mass of the solution (m) is 200.0 mL with a density of 1.00 g/mL, and the heat capacity (c) is 4.184 J/g°C.

First, calculate the mass of the solution (m):
mass of the solution = volume of the solution * density
mass of the solution = 200.0 mL * 1.00 g/mL

Now, calculate the heat (q) using the equation above:
q = mass of the solution * heat capacity * ΔT

Finally, substitute the values for q and n into the equation ΔHrxn = q / n to find the molar heat of reaction (ΔHrxn). Remember to convert the units as necessary to get the answer in kJ/mol.