(1) 2 Ni(s) + O2 (g) --> 2NiO(s) delta H= -479.4 kJ
(2) Ni(s) + Cl2(g) --> NiCl2(s) delta H= -305.3 kJ
Using equations 1 and 2 and Hess's Law, determine the amount of moles Nickel (ii) Chloride that was combusted given the following:
volume = 15.45 L
pressure = 2.29 atm
*each time it is performed, the combustion on a specific mass of NiCl2 required 58.2 kJ of energy
To determine the amount of moles of Nickel (II) Chloride (NiCl2) that was combusted, we need to use Hess's Law, which states that the enthalpy change of a reaction is the sum of the enthalpy changes of the individual steps of the reaction.
1. First, let's calculate the moles of O2 that reacted by using Equation (1):
From Equation (1): 2 Ni(s) + O2 (g) -> 2 NiO(s) delta H = -479.4 kJ
Since the reaction coefficient of O2 is 1, the enthalpy change of the reaction for 1 mole of O2 is -479.4 kJ.
2. Now, let's calculate the moles of Cl2 that reacted by using Equation (2):
From Equation (2): Ni(s) + Cl2(g) -> NiCl2(s) delta H = -305.3 kJ
Since the reaction coefficient of Cl2 is 1, the enthalpy change of the reaction for 1 mole of Cl2 is -305.3 kJ.
3. Next, we need to find the number of moles of energy required to combust the given volume of 15.45 L at a pressure of 2.29 atm. We can use the ideal gas law for this:
PV = nRT
Given:
Volume (V) = 15.45 L
Pressure (P) = 2.29 atm
R = Ideal gas constant = 0.0821 L·atm/mol·K (at standard temperature and pressure)
T = standard temperature (typically 298 K)
By rearranging the ideal gas law, we can solve for moles (n):
n = PV / RT
4. Now, calculate the moles of energy required to combust 58.2 kJ:
Using the equation ΔH = n * ΔH, we can rearrange it to solve for moles (n):
n = ΔH / ΔH
Given:
ΔH = -58.2 kJ
Now, we can calculate the moles using the equation n = ΔH / ΔH.
5. Finally, we need to combine the information obtained from steps 1 and 2 with the moles calculated in step 4 to determine the amount of moles of NiCl2 that was combusted based on the given enthalpies:
From Equation (1): 2 Ni(s) + O2 (g) -> 2 NiO(s) delta H = -479.4 kJ
From Equation (2): Ni(s) + Cl2(g) -> NiCl2(s) delta H = -305.3 kJ
Since the coefficients of NiO and NiCl2 are both 2 in Equation (1) and Equation (2) respectively, the amount of moles of NiCl2 combusted will be twice the moles of O2 and Cl2.
Remember to convert the moles of O2 and Cl2 obtained earlier to moles of NiCl2 by multiplying them by 2.
That should give you the amount of moles of Nickel (II) Chloride (NiCl2) that was combusted based on the given volume, pressure, and energy required.