Answer:
+125.4 KJmol-1
Explanation:
∆H C4H10(g) = -2877.6kJ/mol
∆H C(s)=-393.5kJ/mol
∆H H2(g) = -285.8
∆H reaction= ∆Hproducts - ∆H reactants
∆H reaction= (-2877.6kJ/mol) - [4(-393.5kJ/mol) +5(-285.8)]
∆H reaction= +125.4 KJmol-1
The conversion of volume to moles at STP is 1 mole.
The ideal gas equation is given as :
P V = n R T
where,
P = pressure of the gas
V = volume of the gas
n = ?
R = constant = 0.823 atm L / mol K
T = temperature
At STP , the pressure is 1 atm and the temperature is 273.15 K, the volume At STP is 22.4 L.
moles , n = P V / R T
n = ( 1 × 22.4 ) / (0.0823 × 273.15)
n = 1 mole
Thus, at STP , the number of moles is 1 mol.
To learn more about moles here
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The Oxyfuel gas or flame refers to a group of welding processes that use the flame produced by the combination of a fuel gas and oxygen as the source of heat.
<u>Explanation:</u>
- Oxy-fuel welding is a process that utilizes fuel gases and oxygen to weld metals. Oxyfuel gas or flame refers to a group of welding processes that utilize the flame delivered by the blending of fuel gas and oxygen as the source of heat.
- This flame is utilized for cutting and welding of two metallic pieces. This is done due to the heat produced by cutting and welding of two metallic pieces together by heating to the melting point.
- An oxyhydrogen flame is utilized for cutting and welding of two metallic pieces due to the heat produced by the flame, i.e, 2800 ° C. At this temperature, the metal gets softened effectively and thus it can easily separate or welded together.
The answer to this question would be the second option or B (The moon's orbit is closer to Earth.) because there are multiple different high tides that are caused by either the moon being unusually close to the Earth or the moon is at it's Quarterly or New Moon phases.
Hope that this helped you! :D