Calorimetry and Standard Enthaply question: Manganese reacts with sulfuric acid

Question

Calorimetry and Standard Enthaply question:

Manganese reacts with sulfuric acid to produce manganese (II) sulfate and hydrogen gas.

Mn(s) + H2SO4(aq) ---> MnSO4(aq) + H2(g)

When 1.230g of Mn is combined with enough sulfuric acid to make 100.0mL of solution in a Thermo bottle calorimeter (heat capacity is 58.9 J/°C), all of the Mn reacts raising the temperature of the solution from 24.1°C to 34.5°C. (Assume that the specific heat capacity of the solution is 4.18 J/g°C and the density is 1.02g/mL.)

A) Is this reaction exothermic?

B) What is the heat (q) in Kg for the reaction according to the process described above?

C) Find H°rxn for the chemical reaction as written above.

D) Consider the above given reaction. How many grams of manganese are needed if 895.0kJ of heat are released?

Explanation / Answer

18Amount of heat given =heat taken by solution+ heat taken by calorimeter=

Heat given to the solution=100 (volume of solution )*1.02 denisty *(g/ml) *4.18 specific heat ( j/g.deg.c)* (34.5-24.1) Temperature difference= 4434.144 Joules

Heat taken by calorimeter= 58.8J/g.deg.c* (34.5-24.1)= 612.56 Joules

ttoal heat released is taken by Solution and Bomb calorimeter and hence heat released= 4434.144+612.56 joules=5046.704 joules

The reactino is exothermic

Heat release per kg = 5046.704/1.23= 4103.011 joules/kh

for the reaction

Mn(S)+ H2SO4(aq) ----> MnSO4 (aq)+ H2(g)

heat of reaction =delH products-delH reactants

= delH of MnSO4+ delH of H2-{ delH of Mn+ delH of H2SO4)= -1130 KJ.1+0-{0+909.27 Kj) =-220.83KJ

1 mole of Mn gives rise to-220.83Kj

atomic weight of Mn= 55

220.83 Kj are produced from 55 gms of Mn

895 Kj are produced from (895/220.83)*55=222.9 gms

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.