Enthalpy of formation is calculated by subtracting the total enthalpy of formation of the reactants from those of the products. This is called the HESS' LAW.
ΔHrxn = ΔH(products) - ΔH(reactants)
Since the enthalpies are not listed in this item, from reliable sources, the obtained enthalpies of formation are written below.
ΔH(C2H5OH) = -276 kJ/mol
ΔH(O2) = 0 (because O2 is a pure substance)
ΔH(CO2) = -393.5 kJ/mol
ΔH(H2O) = -285.5 kJ/mol
Using the equation above,
ΔHrxn = (2)(-393.5 kJ/mol) + (3)(-285.5 kJ/mol) - (-276 kJ/mol)
ΔHrxn = -1367.5 kJ/mol
<em>Answer: -1367.5 kJ/mol</em>
In order to determine if a reactant is in excess or limiting, we must first know the required amount of reactants. This is referred to as the stoichometric amount of reactant, and it is obtained from the chemical equation.
From the equation, we form a ratio of the reactants. The reactant supplied in excess of that ratio is the excess reactant, while the other is the limiting reactant.
Answer:
solution concentration
Explanation:
Among the options given in the above question, solution concentration will affect the rate of a chemical reaction. This is because an increase in reagent concentration speeds up the reaction because there will be a greater number of reagent particles per unit volume, increasing the likelihood of effective collisions between them.
In addition to concentration, the factors that can influence the rate of a chemical reaction are temperature, catalyst, pressure and contact surface.
Answer:
0.217 M NaOH
Explanation:
M1V1 = M2V2
M1 = 0.312 M HCl
V1 = 17.4 mL HCl
M2 = ?
V2 = 25.0 mL NaOH
Solve for M2 --> M2 = M1V1/V2
M2 = (0.312 M)(17.4 mL) / (25.0 mL) = 0.217 M NaOH
