Answer:
P = 14.1 atm
Explanation:
Given data:
Mass of methane = 64 g
pressure exerted by water vapors = ?
Volume of engine = 24.0 L
Temperature = 515 K
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O + energy
Number of moles of methane:
Number of moles = mass / molar mass
number of moles = 64 g/ 16 g/mol
Number of moles = 4 mol
Now we will compare the moles of water vapors and methane.
CH₄ : H₂O
1 : 2
4 : 2/1×4 = 8 mol
Pressure of water vapors:
PV = nRT
R = general gas constant = 0.0821 atm.L/mol.K
P = 8 mol × 0.0821 atm.L/mol.K× 515 K / 24.0 L
P = 338.25 atm.L/ / 24.0 L
P = 14.1 atm
The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the surface, probably by the use of a bleaching agent.
Answer:
0.085 moles of N₂O₅ are needed
Explanation:
Given data:
Mass of NO₂ produces = 7.90 g
Moles of N₂O₅ needed = ?
Solution:
2N₂O₅ → 4NO₂ + O₂
Number of moles of NO₂ produced :
Number of moles = mass/ molar mass
Number of moles = 7.90 g/ 46 g/mol
Number of moles = 0.17 mol
now we will compare the moles of NO₂ with N₂O₅.
NO₂ : N₂O₅
4 : 2
0.17 : 2/4×0.17 = 0.085 mol
Thus, 0.085 moles of N₂O₅ are needed.
Answer:
Energy in the campfire originates from the potential chemical energy of the wood, before it is burnt to warm and give light around the campfire.
Explanation:
For a camp fire, the energy input is in the form of the potential chemical energy, stored up in the firewood used to fuel the flame.
The energy output is in the form of heat energy that the campfire radiates all around, light energy given off from the flame, and a little bit of sound energy, heard in the cracking of the firewood as they burn in the flame.
chemical energy ⇒ heat energy + light energy + sound energy
