Answer:
1. 1568 J
2. 0 J
3. 1176 J
Explanation:
PE = mgh
(PE = Potential Energy) = (m = mass)(g = gravitational force which is 9.8)(h = height)
1. (3)(9.8)(20) = 1568 J
2. PE = (3)(9.8)(0) = 0 J
3. (5)(9.8)(24) = 1176 J
3 Sig FIgs in 303,000 mm
Any nonzero is a sig fig.
Any zero between two non zeros is a sig fig.
25 moles of C3H8 will be produced from 75 moles of CO2.
<h3>Mole calculation</h3>
To find the value of moles of a product from the number of moles of a reactant, it is necessary to observe the stoichiometric ratio between them:

Analyzing the reaction, it is possible to see that the stoichiometric ratio is 1:3, so we can perform the following expression:
C3H8 CO2


So, 25 moles of C3H8 will be produced from 75 moles of CO2.
Learn, more about mole calculation in: brainly.com/question/2845237