Question

Very unsure on my answers for these 2 questions. I really have no idea what I'm doing. Could someone please explain? Will give medal and maybe become a fan if someone would just help me understand! Please?

1. Which of the following energy yields is likely to have come from a fission or fusion reaction?
1.0 × 10^2 kJ/mol

2.5 × 10^2 kJ/mol

1.2 × 10^3 kJ/mol

*This one??? 1.4 × 10^11 kJ/mol


2. In a nuclear reaction, a change in mass of 1.0 × 104 g occurs. What is the corresponding change in energy? Use the formula E = mc2.
9.0 × 10^3 kJ

*My best guess... 9.0 × 10^6 kJ

9.0 × 10^9 kJ

9.0 × 10^12 k

Answer 1

For 1: 1 mol is at least 1 gram (for Hydrogen)
If you calculate E = mc^2, you get 9x10^13, your guess is right.

Answer 2

Oh good! Thank you so much!

Answer 3

In 2: If the mass is 10 kg, E = 9x10^17 J.
The last choice is closest.

Answer 4

Ok...I think I understand. That makes sense. Thanks again! I really appreciate it!

Answer 5

E= 10 kg x (3x10^8 m/s)^2 = 9.0 x 10^17 J

Answer 6

U are welcome!

Answer 7

I chose the answer you said was the right one and I got it wrong. :( My guess was correct. Oh well! You've been very helpful and I thank you for trying.

Answer 8

Are you sure the mass is right? I calculated
Second one with m = 10 kg.