Answer:
ΔH for formation of 197g Fe⁰ = 1.503 x 10³ Kj => Answer choice 'B'
Explanation:
Given Fe₂O₃(s) + 2Al⁰(s) => Al₂O₃(s) + 2Fe⁰(s) + 852Kj
197g Fe⁰ = (197g/55.85g/mol) = 3.527 mol Fe⁰(s)
From balanced standard equation 2 moles Fe⁰(s) => 852Kj, then ...
3.527 mole yield (a higher mole value) => (3.527/2) x 852Kj = 1,503Kj (a higher enthalpy value).
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NOTE => If 2 moles Fe gives 852Kj (exo) as specified in equation, then a <u>higher energy value</u> would result if the moles of Fe⁰(s) is <u>higher than 2 moles</u>. The ratio of 3.638/2 will increase the listed equation heat value to a larger number because 197g Fe⁰(s) contains more than 2 moles of Fe⁰(s) => 3.527 mole Fe(s) in 197g. Had the problem asked for the heat loss from <u>less than two moles Fe⁰(s)</u> - say 100g Fe⁰(s) (=1.79mole Fe⁰(s)) - then one would use the fractional ratio (1.79/2) to reduce the enthalpy value less than 852Kj.
Kinetic energy is associated with the motion of an object.
Since the object is at rest on the ground, its velocity is zero.
Since kinetic energy is directly proportional to the square of velocity, kinetic energy of the ball on the ground is zero.
Answer: The final pressure is 34.48kPa
Initial Pressure P1 = 55.16kPa
Initial Volume V1 = 0.500L
Final Pressure P2 = ?
Final Volume V2 = 0.800L
Boyle's law P1V1 = P2 V2
P2 = P1V1/V2
P2 = 55.16*0.5/0.8
P2 = 34.48kPa
Solving part-1 only
#1
KMnO_4
- Transition metal is Manganese (Mn)
#2
Actually it's the oxidation number of Mn
Let's find how?




- x is the oxidation number
#3
- Purple as per the color of potassium permanganate
#4

Answer:
Mass of carbon = 109.1 g
Explanation:
Given data:
Mass of carbondioxide = 400 g
Mass of carbon = ?
Solution:
Molar mass of carbon = 12 g/mol
Molar mass of CO₂ = 44 g/mol
Mass of carbon in 400g of CO₂:
Mass of carbon = 12 g/mol/44 g/mol × 400 g
Mass of carbon = 109.1 g