Edexcel Jan 2017 (IAL) Paper 4 Q6

Answers available below

5 There is a decrease in the entropy of the system when A a gaseous molecule decomposes into two smaller gaseous molecules. B a solid decomposes to form a gas. C a vapour condenses. D a solid melts. (Total for Question 5 = 1 mark) 6 What is the enthalpy change for dissolving sodium chloride in water? NaCl(s) + aq (cid:111) Na+(aq) + Cl (aq) (cid:507)Hsol = (cid:507)Hsolution (cid:507)Hhyd = (cid:507)Hhydration (cid:507)Hsol = + Lattice energy of NaCl + (cid:507)Hhyd Na+ + (cid:507)Hhyd Cl (cid:507)Hsol = + Lattice energy of NaCl(cid:507)Hhyd Na+(cid:507)Hhyd Cl (cid:507)Hsol =Lattice energy of NaCl(cid:507)Hhyd Na+(cid:507)Hhyd Cl (cid:507)Hsol =Lattice energy of NaCl + (cid:507)Hhyd Na+ + (cid:507)Hhyd Cl (Total for Question 6 = 1 mark) 7 Energy is given out when one mole of gaseous sodium ions is hydrated. Na+(g) + aq (cid:111) Na+(aq) This reaction is more exothermic than the corresponding reaction for potassium ions, K+(g), because A sodium compounds are more soluble than potassium compounds. the first ionisation energy of sodium is greater than the first ionisation energy of potassium. the lattice energies of sodium compounds are more exothermic than the lattice energies of corresponding potassium compounds. D the radius of the Na + ion is less than the radius of the K+ ion. Use this space for any rough working. Anything you write in this space will gain no credit. (Total for Question 7 = 1 mark) *P48372RA0428* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br />

Show answer