PLEASe HELP ME WITH THIS BIG EQUATION!!!!!!! ANY HELP WILL BE GREATLY APPRECIATED?

Question

Use the following information to calculate the mass lost when 2 moles of hydrogen atoms fuse with 2 neutrons to form 1 mole of helium.

The molar mass of hydrogen 1 over1 H= 1.00782522 g

The molar mass of a neutron 1over0 n= 1.00807134 g

The molar mass of helium 4over2 He= 4.00260361 g

The balanced nuclear reaction is 2 1over1 H+ 2 1over0 n --> 4over2 He + energy




Question B.

According to Einstein's question, conversion of one gram of mass yields 9*10^10kJ of energy. How much energy is released in the above reaction?

I know this is a lot of work but any help I meen any help will be greatly cherished and apretiated

Answer 1

This really isn't all that hard -- just a bit confusing.

When you do the fusion reaction, some mass is lost -- let's figure out how much:

combined mass of hydrogen atoms and neutrons = 2*1.00782522 + 2*1.00807134 = 4.03179312 grams

mass of helium nuclei produced = 4.00260361 grams

4.03179312 - 4.00260361 = 0.02918951 grams "missing"

the missing mass has been converted to energy according to Einstein's equation, E = mc²

One gram of mass converted into energy releases 9E10 kJ, so the reaction of two moles of hydrogen atoms with two moles of neutrons to make one mole of helium nuclei is:

0.02918951 grams * 9E10 kJ/gram = 2,627,055,900 kJ

which is one heck of a bang! That wasn't so hard, was it?

Answer 2

You laid out the question so thoroughly that you've almost solved it yourself.

As you say, you start out with 2 hydrogen atoms and 2 neutrons.
So you need to add up the mass of 2 H's and 2 n's using the values you show in the problem.
You end up with 1 helium atom, with the mass shown in the problem.
So subtract the helium atom's mass from the sum of the "ingredients," and you'll see how much mass you lost.

For question B, you just multiply the number of grams of mass that was lost (a fraction of a gram, actually) by 9 * 10^10kJ to determine the amount of energy released when creating 1 mole of He.

Incidentally, at the beginning of your question, you meant to write "2 moles of neutrons," rather than "2 neutrons."

Answer 3

The two atoms of H weigh 2 x 1.00782522 = 2.01565044g.
The two neutrons weigh 2 x 1.00807134 = 2.01614268g.
The four particles together weigh 4.03179312g.
By contrast, an atom of He weighs 4.00260361g.
Subtracting the weight of a He atom from the weight of the four particles that went into making it gives 0.02918951g.
This is the mass that is lost.
Because the value of the energy yield, 9 x 10^10kJ, is only given to one significant figure, I shall take the mass lost as 3 x 10^-2 g, which also has only one significant figure.
Multiplying the two gives 27 x 10^8 kJ. This is 3 x 10^7 kJ to one significant figure.

Answer 4

For any reaction the energy released can be calculated from E=delta(m) c^2. So, you need to find delta m (the loss of mass) for your equation. Take the mass of the helium atom and subtract from that the sum of the masses of the reactants (2 X hydrogen's mass + 2 X the neutron mass). Next convert that mass into kilograms (divide by 1000). If you multiply that by the square of the speed of light (9X10^16) you have the energy change for the reaction in Joules.