TEST 1
Date:
Computer test Mark: ____/9
Surname:
Written exam Mark: ____/22
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Proposed Mark: ____/30
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Ex 1) Balance the following equation and calculate the moles of BCl3 produced from 6 grams of
B2H6 and 100 grams of Cl2
B2H6(g) + Cl2(g)  BCl3(g) + HCl(g)
Then, calculate the H° at 25°C for the above reaction knowing that:
H° at 25°C= -112.5 kJ
BCl3(g) + 3 H2O(l)  H3BO3(s) + 3HCl(g)
B2H6(g) + 6 H2O(l)  2 H3BO3(s) + 6 H2(g)
½ H2(g) + ½ Cl2(g)  HCl(g)

H° at 25°C= -493.4 kJ
H° at 25°C= -92.3 kJ
Draw and briefly describe the Lewis structure for BF3 (answer briefly 1-2 sentences).
Ex 2) 1 mole of SO2 and 1 mole of NO2 are inserted in a 1 liter flask and the following equilibrium is
established:
SO2(g) + NO2(g)  SO3(g) + NO(g)
At equilibrium there are 0.6 moles of SO3.Then, without changing the temperature, 30 g of NO are
introduced in the flask. Calculate the moles of SO2 and NO2 after the new equilibrium has been
established.
Would the change of pressure affect the equilibrium (answer briefly 1-2 sentences).
TQ1) Describe what is a concentration cell, draw one example describing the reactions at the
electrodes and provide the Nernst equation for the cell potential.
TQ2) Describe the main properties and classification of amines, providing examples. Write the
general condensation reaction between an amine and a carboxylic acid.