Write a balanced equation for the combustion of c7h16(l) (heptane) -- i. e. its reaction with o2(g) forming the products co2(g) and h2o(l). given the following standard heats of formation: δhf° of co2(g) is -393.5 kj/mol δhf° of h2o(l) is -286 kj/mol δhf° of c7h16(l) is -187.8 kj/mol what is the standard heat of reaction (δh°) for the combustion reaction of c7h16(l)? -4854.7 kj calculate the difference, δh-δe=δ(pv) for the combustion reaction of 1 mole of heptane. (assume standard state conditions and 298 k for all reactants and products.)

The standard enthalpy of reaction = -4854.7kJ

The difference: ΔH-ΔE = Δ(PV) = Δn.R.T = 9910.288 J ≈ 9.91 kJ    

Explanation:

The balanced chemical equation for the combustion of heptane:

C₇H₁₆ (l) + 11 O₂ (g) → 7 CO₂ (g) + 8 H₂O (l)

Given: The standard enthalpy of formation () for: C₇H₁₆ (l) = -187.8 kJ/mol, O₂ (g) = 0 kJ/mol, CO₂ (g) = -393.5 kJ/mol, H₂O (l) = -286 kJ/mol

To calculate the standard enthalpy of reaction () can be calculated by the Hess's law:

Here, is the stoichiometric coefficient

⇒

⇒

⇒

To calculate the difference: ΔH-ΔE=Δ(PV)

We use the ideal gas equation: P.V = n.R.T

⇒ ΔH-ΔE=Δ(PV) = Δn.R.T

Given: Temperature:T = 298K, R = 8.314 J⋅K⁻¹⋅mol⁻¹

Δn = number of moles of gaseous products - number of moles of gaseous reactants = (7)- (11) = (-4)

⇒ ΔH-ΔE=Δ(PV) = Δn.R.T = (-4 mol) × (8.314 J⋅K⁻¹⋅mol⁻¹) × (298K) = 9910.288 J = 9.91 kJ                              (∵ 1 kJ = 1000J )

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.