Question

)1. Sulfur dioxide is produced in enormous amounts for sulfuric acid production. It melts at -73 deg Celsius and boils at -10 deg Celsius. Its H fus is 8.619 kJ/mol and its H vap is 25.73 kJ/mol. The specific heat capacities of the liquid and gas are 0.995 J/g.K and 0.622 J/g.K respectively. How much heat is required to convert 8.500kg of solid SO2 at the melting pt. to a gas at 60 deg Celsius?

2.what is the strongest forces in a sample of solid MgCl2

3.rank the following in order of increasing viscosity ? a)CH3OH b)CH3CH3 c)H2C=O   

a<c<b, b<c<a c<a<b a<b<c b<a<c c<b<a

Answer 1

Ans:-1) Given =8.619KJ/mol

=25.73KJ/mol

mass of SO₂ =8.5Kg =8500g

Molar mass of SO₂ = 64.06g

Number of moles of SO₂ =Given mass /molar mass

                                    = 8500/64.06

                                     = 132.68moles of SO₂

Let us first calculate the heat with the help of and

Now H₁ = moles of SO₂ x

              =132.68x8.619

              = 1143.63KJ

H₂ = moles of SO₂x

      =132.68x25.73

      = 3413.8KJ

Now given specific heat of liquid c₁ =0.995J/gK

melting point of SO₂ = -73⁰C

boiling point of SO₂ = -10⁰C

Change in temperature = -10+73

                                  = 63⁰C

Now H₃ = mc₁

             = 8500x0.995x63

              = 532822.5J

              = 532.8225KJ

Now given specific heat of gas c₂ = 0.622J/gK

initial temperature = -10⁰C

final temperature = 60⁰C

Change in temperature = 70⁰C

H₄ = mc₂

     = 8500x0.622x70

     = 370090J

     =370.09KJ

Now total heat = H₁+H₂+H₃+H₄

                      = 1143.63+3413.8+532.8225+370.09

                      = 5460.3425KJ

Ans 2) In MgCl₂ , Mg²⁺ and Cl^- ions are held together by ionic bond, so the ion-ion interaction will be the strongest force.

Ans 3) The correct order of increasing viscocity will be b<c<a , because CH₃OH will have more viscocity than other two compound because it has strong hydrogen bonding and ethane will have lowest viscocity because its force of attraction between the molecules are the weakest.