Answer:
4.16 * 10²⁴ particles
Explanation:
1. We convert from grams to moles
4 g NaCl / 58 g of NaCl = 0.0689655172 moles
-> 0.0690 moles
2. Now we will convert from moles to particles by multiplying by avogadro's number..
0.0690 * 6.022 *10²³ = 4.15518 * 10²⁴ particles or 4.16 * 10²⁴ particles
<span>Actually, the heat of reaction hrxn s calculated by taking
the sum of the heats of formation of the products minus the sum of the heats of
formation of the reactants. However, at heat of formations of pure elements at
atmospheric conditions is zero, therefore the hf of N2 is not important since
it is zero anyway.</span>
Answer:
The bowling ball has more kinetic energy than the tennis ball
Explanation:
Using the formula 1/2 mass × acceleration we found that the tennis ball had a kinetic energy of 0.75 while the bowling ball had a kinetic energy of 10.5 hence the bowling ball has the ability to do more work
<span>294400 cal
The heating of the water will have 3 phases
1. Melting of the ice, the temperature will remain constant at 0 degrees C
2. Heating of water to boiling, the temperature will rise
3. Boiling of water, temperature will remain constant at 100 degrees C
So, let's see how many cal are needed for each phase.
We start with 320 g of ice and 100 g of liquid, both at 0 degrees C. We can ignore the liquid and focus on the ice only. To convert from the solid to the liquid, we need to add the heat of fusion for each gram. So multiply the amount of ice we have by the heat of fusion.
80 cal/g * 320 g = 25600 cal
Now we have 320 g of ice that's been melted into water and the 100 g of water we started with, resulting in 320 + 100 = 420 g of water at 0 degrees C. We need to heat that water to 100 degrees C
420 * 100 = 42000 cal
Finally, we have 420 g of water at the boiling point. We now need to pump in an additional 540 cal/g to boil it all away.
420 g * 540 cal/g = 226800 cal
So the total number of cal used is
25600 cal + 42000 cal + 226800 cal = 294400 cal</span>
