Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction:

2H2O2(l) → 2H2O(l) + O2(g) ΔH = -196 kJ

Calculate the value of q (kJ) in this exothermic reaction when 4.60 g of hydrogen peroxide decomposes at constant pressure?

-13.3

dH is 196 kJ for 2 mol of H2O2 (i.e. 2*(2+ 32) = 68 g) so

-196 x (4.60/68) = ? kJ for 4.60 g.

Oh, the thrilling world of chemical reactions! It's like they're putting on a show just for us! Now, let's calculate the value of q in this reaction and get dazzled by some numbers!

First, we need to find the number of moles of hydrogen peroxide (H2O2) that decompose. We can calculate that using its molar mass, which is approximately 34 g/mol.

So, 4.60 g of H2O2 is equivalent to (4.60 g) / (34 g/mol) = 0.135 moles of H2O2.

Now, since the reaction is exothermic, we know it releases energy. The value of ΔH tells us that for every 2 moles of H2O2 that decompose, 196 kJ of energy are released.

So, for 0.135 moles of H2O2, the amount of energy released can be calculated as follows:

(0.135 moles H2O2) x (196 kJ) / (2 moles H2O2) = 13.43 kJ

Voilà! The value of q in this exothermic reaction when 4.60 g of hydrogen peroxide decomposes at constant pressure is approximately 13.43 kJ. It's like the reaction couldn't handle all that excitement and had to release some energy to calm down!

To calculate the value of q (kJ) in this exothermic reaction, we first need to determine the amount of heat released per gram of hydrogen peroxide decomposed. This can be done using the stoichiometry of the reaction and the given molar enthalpy change, ΔH.

1. Calculate the molar mass of hydrogen peroxide (H2O2):
The molar mass of hydrogen (H) is 1 g/mol.
The molar mass of oxygen (O) is 16 g/mol.
The molar mass of hydrogen peroxide (H2O2) is (2 x 1 g/mol) + (2 x 16 g/mol) = 34 g/mol.

2. Calculate the number of moles of hydrogen peroxide:
The number of moles of hydrogen peroxide can be found using the formula:
moles = mass / molar mass

moles = 4.60 g / 34 g/mol = 0.135 moles

3. Calculate the heat released per mole of hydrogen peroxide:
The molar enthalpy change (ΔH) of the reaction is given as -196 kJ.

Since the balanced equation shows that two moles of hydrogen peroxide react to produce -196 kJ of heat, we can calculate the heat released per mole of hydrogen peroxide as follows:

heat released per mole = ΔH / moles of H2O2

heat released per mole = -196 kJ / 0.135 moles = -1452.6 kJ/mol

4. Calculate the heat released for 4.60 g of hydrogen peroxide:
To calculate the heat released for the given mass of hydrogen peroxide, we need to multiply the heat released per mole by the number of moles of hydrogen peroxide.

heat released = heat released per mole x moles of H2O2

heat released = -1452.6 kJ/mol x 0.135 moles = -196.02 kJ

Therefore, the value of q (kJ) in this exothermic reaction, when 4.60 g of hydrogen peroxide decomposes at constant pressure, is approximately -196.02 kJ.