Question

1.  How much heat is needed to raise the temperature of 1.50 g of aluminum metal from 23.2 °C to

                30.5 °C?  (Specific heat capacity of aluminum is 0.90 J/g-K).

2.  Given the following thermochemical equation:  

       DH = -1107 kJ          

    How many kJ of heat are released when 15.75 g of Ba(s) reacts completely with oxygen to

   form BaO(s)?

               

3.            Mothballs are composed primarily of the hydrocarbon naphthalene (C₁₀H₈). When 1.25 g    naphthalene is burned in a bomb calorimeter, the temperature rises from 25.25 °C to 34.33 °C.

               (Heat capacity of calorimeter 5.11 kJ/°C). Calculate:

1. The heat of reaction per gram of naphthalene
2. The heat of reaction per mole of naphthalene

4.           Given the following standard enthalpy of formations: ΔH°_f  [C₂H₅OH(l) =-277.7 kJ/mol];  

  ΔH°_f  [CH₃CO₂H(l)   = -484.5 kJ/mol];  ΔH°_f  [H₂O(l) = -285.8 kJ/mol]; ΔH°_f\[O₂(g) = 0 kJ/mol].

               Calculate the DH_rxn for the reaction.

              

5.           Zinc metal reacts with hydrochloric acid according the following balanced equation.

                 Zn(s) + 2HCl(aq) à ZnCl2(aq) + H₂(g)

               When 0.115 g of Zn(s) dissolves in 50.0 mL of HCl in a coffee-cup calorimeter, the temperature rises from 22.5 °C to 23.7 °C. Assume 1.0 g/mL for density of the solution and 4.18 J/g °C as the specific heat capacity, calculate:

1. DH_rxn in kJ per mole of Zn(s)
2. DH_rxn in kJ per gram of Zn(s)

6. Given the following thermochemical reactions

                                               ΔH = -180 kJ

                                           ΔH = -112 kJ

         Calculate the enthalpy change of the reaction of nitrogen with oxygen to produce nitrogen

        dioxide.

                   DH _rxn= ?

Answer 1

To=mc AT Ans Q = amount of heat (J) me mass (3) c= specific neat (J/gne) AT = Change in temp.com Mun (K 1°c) Here we have - xro m = 1.50g of Al s AT= 30.5 c - 23.2°C = 7.3°C c = 0.90 J/g.k =(7.3k Difference in Kelvin scale } elsius scale is SAME H plugging values, Q = (1.50) (0.90)(7-3) MON kindly 2) I = 9.865 submit Different Questions seperately Please Rate on