1. if you have a 1-g sample of po-218, how many grams would you
have after 6 minutes? after 18 minutes?

a) 0.25 g b) 0.01542 g

Explanation:

Half life of Po-218 = 3.04 minutes

initial mass = 1 g

after 3.04 minutes it will remain 0.5 g

after another 3.04 minutes it will remain 0.25 g

After 6 minutes it will remain approx 0.25 g

B) after another 3.04 minutes it will remain 0.125 g

after another 3.04 minutes it will remain 0.0625 g

after another 3.04 minutes it will remain 0.03125 g

after another 3.04 minutes it will remain 0.015625 g

After 18 minutes it will remain approx 0.01542 g

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :