1. D
2. D
3. B
Just took the quiz and and I got these answers right.
Answer:
c)
Explanation:
The reaction between ethene and HBr is:
CH2=CH2 + HBr → CH3CH2Br
Thus, the double bond C=C and the bond H-Br were broken, and the bonds C-C, C-H and C-Br were formed. The enthalpy of the reaction (the energy change), is the sum of the enthalpies of the reactions that were broken with the bonds that were created.
To break a bond, it's necessary to the molecule to gain energy, thus the process is endothermic and H>0, and to form a bond, it's necessary to release energy, and so H<0, so:
ΔH = ∑n*Hbroken - ∑n*Hformed, where n is the coefficient of the substance, so:
ΔH = (612 + 366) - (348+412+276)
ΔH = -58 kJ/mol
The minus signal indicates that the energy was released.
Where's the multiple choice for this
Answer:
D) Rate = K [NO2][Cl2]
Explanation:
2 NO2 + Cl2 → 2 NO2Cl (overall reaction)
NO2 + Cl2 → NO2Cl + Cl (slow)
NO2 + Cl → NO2Cl (fast)
The rate-determining step is the slowest step in a reaction mechanism. Because it is the slowest, it determines the rate of the overall reaction.
Rate of reaction is typically given as;
Rate = K [Reactants]
In the slow step i the reaction mechanism, the reactants are; NO2 and Cl2. Since both are not intermediates, there is no need for further working out.
Rate = K [NO2][Cl2]
I think the compound that has the highest boiling point is CCl4
This is because it has four Carbon-Chloride bonds , while the others have three, two and one and Carbon-hydrogen bonds.
Carbon-Chloride bonds are stronger compared to the Carbon-hydrogen bond, therefore in this case the compound with more C-Cl will have more boiling point.