Question

question 11 (1 point)
m grams of sucrose give enthalpy change of δh kj/mol on combustion. what is the effect on enthalpy change when the mass of the sucrose is doubled?
the enthalpy change remains constant.
the enthalpy change doubles.
enthalpy change is reduced to half.
δh stays the same
enthalpy becomes zero.
question 12 (1 point)
use the following information to answer the next question.
when graphite combines with hydrogen and gaseous oxygen, one mole of ethyl alcohol is formed.
2c(graphite) + 3h₂(g) + ½o₂(g) → c₂h₅oh δf h⁰ = -2777.7 kj/mol

Explanation:

Step1: Relationship between mass and enthalpy change

Enthalpy change (\(\Delta H\)) for a reaction is directly proportional to the amount (in moles) of reactants consumed or products formed.
If the mass of sucrose is doubled, the number of moles of sucrose is also doubled (since \(n=\frac{m}{M}\), where \(n\) is the number of moles, \(m\) is the mass, and \(M\) is the molar mass).

Step2: Effect on enthalpy change

Since \(\Delta H\) is proportional to the number of moles of substance undergoing the reaction, when the number of moles is doubled, the enthalpy change \(\Delta H\) also doubles.

Answer:

The enthalpy change doubles.