ALEV CHEM BORN-HABER CYCLE UPDATED Actual Questions and CORRECT Answers
1 view 0 purchase
Course
ALEV CHEM BORN-HABER CYCLE
Institution
ALEV CHEM BORN-HABER CYCLE
ALEV CHEM BORN-HABER CYCLE
UPDATED Actual Questions and
CORRECT Answers
Define the term electron affinity for chlorine - CORRECT ANSWER- The enthalpy
change / heat energy change / ΔH for the formation of one mole of (chloride)
ions from (chlorine) atoms
A 5.00 g sample of potassium chlorid...
ALEV CHEM BORN-HABER CYCLE
UPDATED Actual Questions and
CORRECT Answers
Define the term electron affinity for chlorine - CORRECT ANSWER✔✔- The enthalpy
change / heat energy change / ΔH for the formation of one mole of (chloride)
ions from (chlorine) atoms
A 5.00 g sample of potassium chloride was added to 50.0 g of water initially at 20.0 °C. The
mixture was stirred and as the potassium chloride dissolved, the temperature of the
solution decreased. - CORRECT ANSWER✔✔- Start a clock when KCl is added to water
Record the temperature every subsequent minute for about 5 minutes
Allow record the temperature at regular time intervals
untilsome time after all the solid has dissolved for M2
Plot a graph of temperature vs time
Extrapolate back to time of mixing = 0 and determine the temperature
The temperature of the water decreased to 14.6 °C.
Calculate a value, in kJ mol−1, for the enthalpy of solution of potassium chloride.
You should assume that only the 50.0 g of water changes in temperature and that
the specific heat capacity of water is 4.18 J K−1 g−1
.
Give your answer to the appropriate number of significant figures. - CORRECT
ANSWER✔✔- Heat taken in = m × c × ΔT = 50 × 4.18 × 5.4 = 1128.6 J
Moles of KCl = 5..6 = 0.0670
Enthalpy change per mole = +1128..0670 = 16 839 J mol-1
= +16.8 (kJ mol-1)
Answer must be given to this precision
The enthalpy of solution of calcium chloride is −82.9 kJ mol−1
.
, The enthalpies of hydration for calcium ions and chloride ions are −1650 and
−364 kJ mol−1, respectively.
Use these values to calculate a value for the lattice enthalpy of dissociation of
Explain why the lattice enthalpy of calcium chloride is different from the lattice enthalpy of
dissociation for magnesium chloride. - CORRECT ANSWER✔✔- Magnesium ion is smaller
than the calcium ion
1
Therefore, it attracts the chloride ion more strongly / stronger ionic bonding
Write an equation for the process that has an enthalpy change equal to the electron affinity of
chlorine - CORRECT ANSWER✔✔- Cl(g) + e → Cl(g)
State symbols essential
Allow e with no charge
This and all subsequent equations must be balanced
In terms of electrostatic forces, suggest why the electron affinity of fluorine has a negative
value. - CORRECT ANSWER✔✔- There is an attraction between the nucleus / protons and
(the added)
electron(s)
A theoretical value for enthalpy of lattice dissociation can be calculated using a
perfect ionic model.
The theoretical enthalpy of lattice dissociation for silver fluoride is +870 kJ mol-1
.
(i) Explain why the theoretical enthalpy of lattice dissociation for silver fluoride is
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller MGRADES. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.49. You're not tied to anything after your purchase.
