Me!
the symbol sb stands for stibnum or stibnite. what is the modern name of this element?

Here is your answer

The modern name of Sb (i.e. stibnum or stibnite) is ANTIMONY.

SOME EXTRA INFORMATION:

Atomic number= 51

Atomic mass= 121.76 u

Electronic configuration: [Kr]4d10 5s2 5p3

HOPE IT IS USEFUL

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 :

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.