Answer:
ΔHrxn = [(1) -1675.5 ( kJ/mole) + (2) 0 ( kJ/mole)] - [(1) -824.3 ( kJ/mole) + (2) 0 ( kJ/mole)]
Explanation:
ΔHrxn = 2ΔHf (Al₂O₃) - ΔHf (Fe₂O₃)
Remember that for pure elements in their standard state of temperature and pressure by definition their standard heats of formation are zero.
ΔHrxn = 2(-1675.7) - (-824.3) kJ/mol
ΔHrxn = 2527 kJ/mol
First let us compute for the number of moles of butane
(molar mass = 58.12 g/mol)
number of moles = 145 g / (58.12 g/mol) = 2.49 mol
<span>We use the ideal
gas equation to calculate the volume:</span>
<span> V = n R T / P</span>
V = 2.49 mol * 62.36367 L torr / mol K * 308.15 K / 745
torr
<span>V = 64.35 L</span>
Answer:
Molecular Formula = C₆H₁₂O₆
Solution:
Molecular formula is calculated by using following formula,
Molecular Formula = n × Empirical Formula ---- (1)
Also, n is given as,
n = Molecular Weight / Empirical Formula Weight
Molecular Weight = 180.2 g.mol⁻¹
Empirical Formula Weight = 12 (C) + 2 (H₂) + 16 (O) = 30 g.mol⁻¹
Son
n = 180.2 g.mol⁻¹ ÷ 30 g.mol⁻¹
n = 6
Putting Empirical Formula and value of "n" in equation 1,
Molecular Formula = 6 × CH₂O
Molecular Formula = C₆H₁₂O₆
