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SOVA2 [1]
3 years ago
7

For a particular isomer of C8H18, the combustion reaction produces 5104.1 kJ of heat per mole of C8H18(g) consumed, under standa

rd conditions. C8H18(g)+252O2(g)⟶8CO2(g)+9H2O(g)ΔH∘rxn=−5104.1 kJ/mol What is the standard enthalpy of formation of this isomer of C8H18(g)?
Chemistry
1 answer:
Vladimir79 [104]3 years ago
3 0

Answer:

Explanation:

Hello,

Considering the chemical reaction, the enthalpy of reaction is given by:

ΔH°rxn=ΔfHCO2+ΔfHH2O-ΔfHC8H18

(ΔfHO2=0)

Taking into account that the reaction produces energy, ΔH°rxn is negative. No, solving for ΔfHC8H18:

ΔfHC8H18=-ΔH°rxn+8*ΔfHCO2+9*ΔfHH2O

ΔfHC8H18=-(-5104.1 kJ/mol)+9*(-292.74kJ/mol)+8*(-393.5 kJ/mol)

ΔfHC8H18=-678.56 kJ/mol

Best regards.

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WINSTONCH [101]

Answer:

the volume occupied by 3.0 g of the gas is 16.8 L.

Explanation:

Given;

initial reacting mass of the helium gas, m₁ = 4.0 g

volume occupied by the helium gas, V = 22.4 L

pressure of the gas, P = 1 .0 atm

temperature of the gas, T = 0⁰C = 273 K

atomic mass of helium gas, M = 4.0 g/mol

initial number of moles of the gas is calculated as follows;

n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1

The number of moles of the gas when the reacting mass is 3.0 g;

m₂ = 3.0 g

n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol

The volume of the gas at 0.75 mol is determined using ideal gas law;

PV = nRT

PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\  then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L

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4 0
2 years ago
Explain the difference between molecule and compound
nadya68 [22]
Answer:
A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion. All molecules are not compounds.

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2 years ago
How many mL of a stock solution of 2.00 M KNO3 are needed to prepare 100.0 mL of 0.15M KNO3? with work plz
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3 years ago
if 45.0 ml of 1.50 M Ca(OH)2 are needed to neutralize 25.0 ml of HI of unknown concentration, what is the molarity of the HI?
ipn [44]

Answer:

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Explanation:

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<em>(XMV) acid = (XMV) base.</em>

where, X is the no. of (H) or (OH) reproducible in acid or base, respectively.

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