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Arte-miy333 [17]
3 years ago
5

The combustion of 0.0222g of isooctane vapor, C8H18(g), at constant pressure raises the temperature of a calorimeter 0.400 degre

es C. The heat capacity of the calorimeter and water combined is 2.48kJ/degrees C. Find the molar heat of combustion of gaseous isooctane.
Chemistry
1 answer:
saul85 [17]3 years ago
4 0

Answer:

ΔH = 5102.88 KJ/mol

Explanation:

  • Qp = ΔH = CpΔT... constant pressure

∴ Cp = 2.48 KJ/°C

∴ ΔT = 0.400°C

∴ Mw C8H18(g) = 114.22 g/mol

∴ mol C8H18(g) = (0.0222 g)×(mol C8H18/114.22 g) = 1.944 E-4 mol C8H18

⇒ ΔH = (2.48 KJ/°C)×(0.400°C) = 0.992 KJ

⇒ ΔH = 0.992 KJ/ 1.944 E-4 mol C8H18

⇒ ΔH = 5102.88 KJ/mol

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6 0
3 years ago
The solubility of water in diethyl ether has been reported to be 1.468 % by mass.' Assuming that 23.0 mL of diethyl ether were a
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Explanation:

As it is given that solubility of water in diethyl ether is 1.468 %. This means that in 100 ml saturated solution water present is 1.468 ml.

Hence, amount of diethyl ether present will be calculated as follows.

                          (100ml - 1.468 ml)

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So, it means that 98.532 ml of diethyl ether can dissolve 1.468 ml of water.

Hence, 23 ml of diethyl ether can dissolve the amount of water will be calculated as follows.

          Amount of water = \frac{1.468 ml \times 23 ml}{98.532 ml}

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Now, when magnesium dissolves in water then the reaction will be as follows.

                Mg + H_{2}O \rightarrow Mg(OH)_{2}

Molar mass of Mg = 24.305 g

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Therefore, amount of magnesium present in 0.3427 ml of water is calculated as follows.

           Amount of Mg = \frac{24.305 g \times 0.3427 ml}{18 g}  

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6 0
3 years ago
Calculate the pH of a solution created by placing 2.0 grams of yttrium hydroxide, Y(OH)3, in 2.0 L of H2O. Ksp for Y(OH)3 is 6.0
oee [108]

Answer:

pH = 8.314

Explanation:

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equil:   S               S         3S

∴ Ksp = [ Y+ ] * [ OH- ]³ = 6.0 E-24

⇒ 6.0 E-24 = ( S )*( 3S )³

⇒ 6.0 E-24 = 27S∧4

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⇒ ( 2.22 E-25 )∧(1/4) = S

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8 0
3 years ago
For double-helix formation, DG can be measured to be 2 54 kJ mol 1 ( 2 13 kcal mol 1 ) at pH 7.0 in 1 M NaCl at 25 8C (298 K). T
levacccp [35]

Answer:

ΔS = -661.0J/mol is the entropy change for the system

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plugging into the equation,

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8 0
3 years ago
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