Can someone help me to check my answer and the way I solve this problem is right or wrong?
Determine the energy required to turn a Na metal atom into a gas phase ion (Na+ (g)).
Ionization energy of Na(g) 499 kJ/mol
Electron affinity of O(g)for2e- 603 kJ/mol
Energy to vaporize Na(s) 109 kJ/mol
O2(g) bond energy 499 kJ/mol
Energy change for the reaction:
2Na(s) + 1/2 O2(g)---> Na2O(s) -416kJ/mol
I think I will use Na(s)-->Na(g) and
Na(g)-->Na+(g)
to solve this problem and this is my answer:
499+(109x2)= 717 kJ/mol
This is my answer.
Please help me out to check my answer and if I did wrong, please help me to show what steps I should do to get the right answer.
Thank you so much.
I would agree with 499 kJ/mol + 109 kJ/mol = ? but I don't know why you multiplied by 2.
To determine the energy required to turn a sodium (Na) metal atom into a gas phase ion (Na+ (g)), you need to consider the different energy changes involved in the process. Let's go through the steps and calculate the energy change.
First, you correctly identified that you need to consider two steps:
1. Na(s) --> Na(g) (Energy required to vaporize sodium)
2. Na(g) --> Na+(g) (Ionization energy)
Let's start with the first step:
Step 1: Na(s) --> Na(g)
The energy required to vaporize sodium (Energy to vaporize Na(s)) is given as 109 kJ/mol. However, in this step, we are converting one Na metal atom, not a mole of Na. So we need to divide the given energy by Avogadro's number (6.022 x 10^23 mol^-1) to get the energy per sodium atom.
109 kJ/mol / (6.022 x 10^23 mol^-1) = 1.81 x 10^-22 kJ
So the energy required to turn one Na metal atom into Na(g) is approximately 1.81 x 10^-22 kJ.
Now, let's move on to the second step:
Step 2: Na(g) --> Na+(g)
The ionization energy of Na(g) is given as 499 kJ/mol. Similar to step 1, we divide this energy by Avogadro's number to get the energy per sodium atom.
499 kJ/mol / (6.022 x 10^23 mol^-1) = 8.28 x 10^-22 kJ
The energy required to turn one Na(g) atom into Na+(g) is approximately 8.28 x 10^-22 kJ.
To calculate the total energy change, we need to sum the energies from both steps:
1.81 x 10^-22 kJ + 8.28 x 10^-22 kJ = 10.09 x 10^-22 kJ
So the total energy required to turn one Na metal atom into Na+ (g) is approximately 10.09 x 10^-22 kJ, or 10.1 x 10^-22 kJ/mol.
Comparing this with your answer of 717 kJ/mol, we can see that there was an error in your calculation. It seems like you multiplied the energy required to vaporize Na(s) (109 kJ/mol) by 2, which is incorrect because we only have one sodium atom in the equation.
To get the correct answer, you should follow the steps outlined above using the correct values, which give a total energy of approximately 10.1 x 10^-22 kJ/mol.
I hope this explanation helps you understand the correct calculation process.