Answer:
Number of moles is 3.0moles
Explanation:
Volume (v) = 67.2L
Pressure at STP = 1atm
Temperature at STP = 273.15K
R = 0.082J/mol.K
Number of moles (n) = ?
From ideal gas equation,
PV = nRT
P = pressure
V = volume of the gas
n = number of moles
R = ideal gas constant
T = temperature of the gas
PV = nRT
solving for n,
n = PV / RT
n = (1.0 * 67.2) / (0.082 * 273.15)
n = 67.2 / 22.398
n = 3.0 moles
The number of moles present is 3.0
Answer:
27.9 mL
Explanation:
To find the new volume, you need to use the Charles' Law equation:
V₁ / T₁ = V₂ / T₂
In this equation, "V₁" and "T₁" represent the initial volume and temperature. "V₂" and "T₂" represent the final volume and temperature.
V₁ = 105 mL V₂ = ? mL
T₁ = 392 °F T₂ = 104 °F
V₁ / T₁ = V₂ / T₂ <----- Charles' Law
105 mL / 392 °F = V₂ / 104 °F <----- Insert values
0.26785 = V₂ / 104 °F <----- Simplify left side
27.9 = V₂ <----- Multiply both sides by 104
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First we need to find the number of moles that 43.9g of gallium metal is. We can do this by finding the molar weight of gallium and cross-multiplying to cancel out units:

So we are dealing with 0.63 moles of gallium metal.
We can take from the balanced equation that 4 moles of gallium metal will react completely with 3 moles of oxygen gas. We can take this ratio and make a proportion to find the amount of oxygen gas, in moles, that will react completely with 0.63 moles of gallium metal:

Cross multiply and solve for x:
4x=1.89
x=47 molesO₂
So now we know that 0.47 moles of oxygen gas will react with 43.9g of gallium metal.