1 How many grams of SiO2 are in 7.22 X 1030 molecules? 2 How many molecules of HBr are in 4 grams?

3 How many molecules are in 2.03 moles NaOH?

4 How many moles are in 519.3 grams of PbNO3?

5 How many formula units are in 100g of NaCl?

6 How many moles are in 8.07 X 1025 atoms of Sulfur?

7 How many Bromine ions are found in 9.73g of MgBr2? 8 How many grams are in 7.23 x1022 molecules of C6H6?

10 How many nitrogen atoms are in 5.85 grams of trinitrogen trioxide? 11 How many moles are present in 4.77g of Carbon Tetrahydride?

answer: the rate of diffusion increases with increase in temperature.

increase in temperature, increases the molecular/particles speed (kinetic energy. diffusion means movement of particles through the material.

generally, the heavier the particle the more it interacts with the environment and more the temperature matters. so higher temperature results in higher diffusion.

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole