69. Solving a chemistry problem

1.25(19) Given a dispersed system with the mass of the dispersed phase m, the density of the dispersed phase m, with particles of the dispersed phase of a certain shape and size: r is the radius of the ball, l is the length of the cube edge (task options are given in Table 1.2).
1. Calculate the dispersion of the system D and the specific surface area Ssp.
2. Calculate the parameters of the particle of the dispersed phase: volume V0, surface S0, mass m0.
3. Calculate the total surface of all particles S and the number of particles N in the dispersed system.
Option 19
The dispersed phase is coal dust, the dispersion medium is air, the shape of the particle is a cube, r (l), m - 6 * 10-5, p * 10-3, kg / m3 - 1.8, m, kg - 8.