True ncifjfjedkxkcnnfenskxkcjcndnenejskkxcfenen
Answer:
ΔH° = -1815 kJ
Explanation:
The balanced chemical equation
C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(l)
tells us that 2220 kJ joules are released in the combustion of one mol propane,C3H8 . So what we need to solve this problem is to find how many moles of propane 20.0 L represent and do the calculation.
To do that, we will be using the Ideal Gas Law since we are told the volume, temperature, and pressure.
PV = nRT ∴ n = PV/RT
P: 1 atm
V: 20.0 L
R= 0.08206 Latm/kmol ( R constant for ideal gases)
T= 25 ºC + 273 = 298 k (Need to convert T to degree Kelvin)
Plugging the values
n = 1 atm x 20.0 L/ (0.08206 Latm/ k mol)
n = 0.82 mol
ΔH° =(-2220 kJ / 1 mol C3H8 ) 0.82 mol C3H8 = -1815 kJ
Answer:
It boils at 100 degrees celsius
Explanation:
It's a commonly known fact
The number of moles in a substance may be calculated using:
Moles = mass / molecular mass
The molecular mass of CH₂Cl₂ is:
12 + 2 * 1 + 2 * 35.5
= 85 grams / mole
Moles = 76.1 / 85
Moles = 0.895
There are 0.90 moles of CH₂Cl₂ present in 76.1 grams.
Balanced chemical equation: C(s) + O₂(g) → CO₂(g).
Oxidation half reaction: C⁰ → C⁺⁴ + 4e⁻.
Reduction half reaction: O₂⁰ + 4e⁻ → 2O⁻².
Carbon is oxidized, it changes oxidation number from zero (in carbon element) to oxidation number +4 (in carbon dioxide).
Oxygen is reduced, it changes oxidation number from zero (in molecule of oxygen) to oxidation number -2 (in carbon dioxide).