Styrene, c8h8, is one of the substances used in the production of synthetic rubber. when styrene burns in oxygen to form carbon dioxide and liquid water under standard-state conditions at 25°c, 42.15 kj are released per gram of styrene. find the standard enthalpy of formation of styrene at 25°c.
(given: ? h°f[co2(g)] = –393.5 kj/mol, ? h°f[h2o(l)] = –285.8 kj/mol, ? h°f[h2o(g)] = –241.8 kj/mol)

ΔH°f(C₈H₈(l)) = 98.80 kJ/mol

Explanation:

Let's consider the combustion of styrene.

C₈H₈(l) + 10 O₂(g) → 8 CO₂(g) + 4 H₂O(l)

42.15 kJ are released per gram of styrene, that is, -42.15 kJ/g. In the balanced equation there is 1 mole of C₈H₈, so the heat released per mole is:

In order to find the standard enthalpy of formation of styrene (ΔH°f(C₈H₈(l))) we will use the following expression.

ΔH°rxn = Σ np . ΔH°f(p) - Σ nr . ΔH°f(r)

where,

ni: moles of reactants and products

ΔH°rxn = 8 mol × ΔH°f(CO₂(g)) + 4 mol × ΔH°f(H₂O(l)) - 1 mol × ΔH°f(C₈H₈(l)) - 10 mol × ΔH°f(O₂(g))

1 mol × ΔH°f(C₈H₈(l)) = 8 mol × ΔH°f(CO₂(g)) + 4 mol × ΔH°f(H₂O(l)) - 10 mol × ΔH°f(O₂(g)) - ΔH°rxn

1 mol × ΔH°f(C₈H₈(l)) = 8 mol × (-393.5 kJ/mol) + 4 mol × (-285.8 kJ/mol) - 10 mol × 0 kJ/mol - (-4390 KJ)

ΔH°f(C₈H₈(l)) = 98.80 kJ/mol

adding or remove a gaseous reactant or product changes the concentrations. if the concentration of reactant or product is increased, the system will shift away from the side in which concentration was increased (i.e. if the concentration of reactants is increased, the system will shift toward the products. if more products are added, the system will shift to form more reactants). conversely, if the concentration of reactant or product is decreased, the system will shift toward the side in which concentration was decreased (i.e. if reactants are removed, the system will shift to form more reactants. if the concentration of products is decreased, the equilibrium will shift toward the products).

explanation:

c)red bank

explanation:

red bank is a borough in monmouth county, new jersey, incorporated in 1908 and located on the navesink river, the area's original transportation route to the ocean and other ports.