Question

A 2.490-g sample of cadmium metal completely reacts

   when placed in a coffee cup calorimeter that contains 75.0 mL of a

dilute sulfuric acid solution (aqueous) (density of 1.03 g/mL) to produce hydrogen gas and dissolved cadmium sulfate.  The chemical reaction is exothermic causing the temperature of the resulting aqueous solution to change from 21.5^oC to 32.5^oC.  

1. Write a balanced chemical equation for the chemical reaction that occurs.

2. Find the enthalpy change, in kJ/mol, for the chemical reaction, assuming the specific heat of the resulting aqueous solution is

4.18 J/(g×C^o) and assuming the coffee cup calorimeter is not involved in any heat exchange.

Answer 1

a) cd (9) + HS04 () — caso, (aq) + H2 (9) 6) mass of Solution = 2.490 g + 15.0ml * 1.03 - m= 79.74 g HEAT RELEASED, E=mc at . 2=790.749x 2018 I x (32.5-21:57c = 3.67 kJ gių NO. Of moles of Coromium = mass of chromium - MOLAR mass of Cadmium 2:4909 112,41 gare = 0.022 moe ENTHALpy CHANGE = R = -3.67 kJ 0.022 moe -166.8 kolmo minus SIGN INDICATES REMTON is tXOTHERMIC.