Answer:
-800 kJ/mol
Explanation:
To solve the problem, we have to express the enthalpy of combustion (ΔHc) in kJ per mole (kJ/mol).
First, we have to calculate the moles of methane (CH₄) there are in 2.50 g of substance. For this, we divide the mass into the molecular weight Mw) of CH₄:
Mw(CH₄) = 12 g/mol C + (1 g/mol H x 4) = 16 g/mol
moles CH₄ = mass CH₄/Mw(CH₄)= 2.50 g/(16 g/mol) = 0.15625 mol CH₄
Now, we divide the heat released into the moles of CH₄ to obtain the enthalpy per mole of CH₄:
ΔHc = heat/mol CH₄ = 125 kJ/(0.15625 mol) = 800 kJ/mol
Therefore, the enthalpy of combustion of methane is -800 kJ/mol (the minus sign indicated that the heat is released).
Re usable glass plates instead of paper plates
I believe the correct response would be A. Energy being absorbed, as temperature increase must for instance occur for the reaction to occur, this increase in temperature for the reacting substances indicates energy being absorbed as the reaction proceeds.
<em>Jorge moves at a rate of 2.45 m / s while cycling along a path in a park; which has a total trajectory of 1.5 km. How long did Jorge take to make that journey?</em>
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Time taken = 612.24 s=10.2 minute
<h3>Further explanation</h3>
Linear motion consists of 2: constant velocity motion with constant velocity and uniformly accelerated motion with constant acceleration
• At constant velocity motion:
the speed of vo = v = constant
acceleration = a = 0
Δx = vt or x = xo + vt
An equation of constant velocity motion
d = distance = m
v = speed = m / s
t = time = seconds
v=2.45 m / s
d=1.5 km=1500 m
Time taken :
Answer:
OK I guess you can do it ok