07222. Solving a chemistry problem

1. The dispersion of the sol is 5*107 m-1. The radius of its constituent particles (m) is equal to:

a)2*10-8 b)5*10-9 c)1*10-8 d)2*108

2. The specific surface area of a sol consisting of cubic particles with a linear size of 3 nm is (m-1):

a)2*108 b)1*109 c)2*109 d)2*10-9

3. The osmotic pressure of a solution with a concentration of 0.005 mol/l at a temperature of 20 C is equal (Pa):

a) 831.4 b) 12.2*103 c) 0.8314 d) 12.2

4. The maximum adsorption of some surfactant is 4*10-12 mol/mm2. The area (m2) occupied by one surfactant molecule in a saturated adsorption layer is equal to:

a) 2.5*10-4 b) 4.2*10-19 c) 2.1*10-19 d) 4.2*10-16

5. The initial partial concentration of particles (m-3) of a sol with a half-coagulation time of 500 s and a coagulation constant of 2 * 10-15 m3/s is:

a) 1018 b) 1015 c) 1012 d) 10-14

6. The ratio of osmotic pressures of sols with the same mass concentrations n1/n2 = 0.001. How do the particle sizes of these sols relate, r1/r2?

a)10 b)1000 c)0.001 d)1

7. The coagulation threshold of a negatively charged sol for KCl is 45 mmol/l, and for AlCl3 -

a) 15 mmol/l b) 0.062 mol/l c) 15 mmol/m3 d) 0.062 mmol/l

8. The ratio of the ionic strengths of the two sols I2/I1 is 100. The ratio of the thicknesses of the diffuse parts λ1/λ2 of the DES is:


a) 100 b) 0.01 c) 0.1 d) 10

9. A capillary with a diameter of 0.2 μm is filled with a liquid whose surface tension is 72 mN/m. The excess pressure (Pa) is equal to:

a)1.440*109 b)1.440*106 c)7.2*105 d)7.2*108

10. Draw the structure of a sol micelle obtained by mixing the following solutions:
10 ml 0.02 M K2SO4 and 8 ml 0.05 M BaCl2