When 0.678 g of Ca metal is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 11.0C 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.
(Note: Pay attention to significant figures. Do not round until the final answer.)
The molar heat of reaction, H rxn, for the reaction of

Ca(s) + 2H+(aq) -> Ca2+(aq) + H2(g)

THANKS! :)

q = mass water x specific heat water x delta T.

Then q/0.678 = ?J/g. Convert that to kJ/mole.

OK. I just read your earlier post.

200 x 4.184 x 11 is correct.
And that number divided by 0.678 is correct for J/g.
Just take that number (J/g) and divide by 1000 to convert to kJ, then multiply by molar mass Ca to convert to kJ/mole.

It is negative fyi

why do you multiply by 200? how to the units of mL just disappear then? what do you do with 1.00 g/mL?

just type it in. it works when its negative.

You would times it by the momentum currency of memorandum which is stated in Hess's law of physics

To find the molar heat of reaction (ΔH_rxn) for the given reaction, we can make use of the equation:

ΔH_rxn = q / n

Where:
- ΔH_rxn is the molar heat of reaction in joules per mole (J/mol)
- q is the heat absorbed or released by the reaction, measured in joules (J)
- n is the number of moles of the limiting reactant

First, we need to find the heat absorbed or released by the reaction (q). This can be calculated using the formula:

q = mcΔT

Where:
- q is the heat absorbed or released by the reaction, measured in joules (J)
- m is the mass of the solution, measured in grams (g)
- c is the specific heat capacity of the solution, measured in J/g*C
- ΔT is the temperature change of the solution, measured in C

Given:
- Mass of the solution (m) = volume of the solution x density of the solution = 200.0 mL x 1.00 g/mL = 200.0 g
- Specific heat capacity of the solution (c) = 4.184 J/g*C
- Temperature change of the solution (ΔT) = 11.0 C

Substituting the given values into the equation, we have:

q = (200.0 g) x (4.184 J/g*C) x (11.0 C)
q = 92096.8 J

Now, we need to determine the number of moles of the limiting reactant. In this case, Ca is the limiting reactant since it is completely consumed according to the balanced chemical equation. The number of moles of Ca can be calculated using its molar mass.

Given:
- Mass of Ca (m) = 0.678 g
- Molar mass of Ca = 40.08 g/mol

Substituting the given values into the equation, we have:

n = m / M
n = 0.678 g / 40.08 g/mol
n = 0.0169 mol

Finally, we can find the molar heat of reaction (ΔH_rxn) using the equation:

ΔH_rxn = q / n
ΔH_rxn = 92096.8 J / 0.0169 mol

Calculating this expression yields the value for ΔH_rxn in J/mol. Note that the significant figures should be maintained throughout the calculation and only rounded at the end, as indicated in the problem statement.