S1-Q4-U4 - L1 all

Given the following data: ΔH^○_f[FeO(s)] = –270kJmol^–1

ΔH^○_f [Fe₂O₃(s)] = –820 kJ mol^–1

Select the expression which gives the enthalpy change, in kJ mol^–1, for the reaction:

2FeO(s) + 1⁄2O₂(g) → Fe₂O₃(s)

• –140

• –1090

• –280

• +280

• –550

The standard enthalpy changes of formation of iron(II) oxide, FeO(s), and aluminium oxide, Al₂O₃(s), are –266 kJ mol^–1 and –1676 kJ mol^–1 respectively.
What is the enthalpy change under standard conditions for the following reaction?
3FeO(s) + 2Al (s)   ->   3Fe(s) + Al₂O₃(s) 

• +878kJ 
• –878kJ 
• –1942kJ 
• –2474kJ 

C₂H₄(g) + H₂(g)   ->   C₂H₆(g)  ∆H°=-137 kJ mol^-1
Which statement about this information is correct?

• The total energy of the bonds broken in the reactants is greater 
  than the total energy of the bonds 
  formed in the product 
• The bonds broken and the bonds made are of the same strength 
• The total energy of the bonds broken in the reactants is less than the total energy of the bonds formed in the product 
• No conclusion can be made about the sums of the bond enthalpies in the product compared with the reactants 

Ethene and iodine react to form 1,2-diiodoethane. The equation for this reaction is shown, the total energy change per mole of ethene is (-24 KJ/mol) if the bond energies are [C-C is 346 ; C=C is 602 ; C-H is 411 ; I-I is 148] , calculate the bond energy of C-I ??

• 2031 KJ

• 387 KJ

• 214 KJ

• 598.5 KJ

Which of the following hydrogen halides has the smallest bond enthalpy?

• HF

• HCl

• HBr

• HI

Chloromethane is produced by the reaction of methane CH₄ with chlorine gas in the presence of UV light. The equation for this reaction is shown.

calculate the molar heat enthalpy for this reaction ?

[C-H = 411 ; H-Cl=428 ; Cl-Cl=240 ; C-Cl=327]

• -104 KJ

• +104 KJ

• +327 KJ

• -250 KJ

The process of dissolution can be considered to involve three steps. Which of the following is not one of these steps?

• The separation of solvent–solute interactions

• The separation of solvent–solvent intermolecular attractions

• The formation of solute–solvent interactions

• The separation of solute–solute attractions

What is the enthalpy change of dilution, Δ𝐻_dil?

• 71.2 KJ

• -13.2 KJ

• -71.2 KJ

• + 13.2 KJ

what do X and Y represent respectively?

• ΔH _melting & Δ H _evaporation

• ΔH _Fusion & Δ H _evaporation

• ΔH _condensation & Δ H _evaporation

• ΔH _Fusion & Δ H _solution

What standard enthalpy change can be defined as the enthalpy change when one mole of a substance transforms from a liquid state to a solid state under standard conditions?

• Standard enthalpy of fusion

• Standard enthalpy of vaporization

• Standard enthalpy of sublimation

• Standard enthalpy of solidification

• Standard enthalpy of condensation