Calculate the number of ions present in 8.2 moles of calcium nitrate

             1.48 × 10²⁵ Ions

Solution:

Calcium Nitrate having a chemical formula Ca(NO₃)₂ is made up of one Ca²⁺ cation and two NO₃⁻ anions. Hence, we can say that each Calcium Nitrate contains three ions respectively.

Therefore,

                1 mole of Ca(NO₃)₂ contains  =  6.022 × 10²³ formula Units

So,

       8.2 mole of Ca(NO₃)₂ will contain  =  X Formula Units

Solving for X,

                      X =  (8.2 mol × 6.022 × 10²³ formula units) ÷ 1 mol

                      X =  4.93 × 10²⁴ Formula Units

As discussed,

                      1 Formula Unit of Ca(NO₃)₂ contains  =  3 Ions

So,

                    4.93 × 10²⁴ Formula units will contain  =  X ions

Solving for X,

                      X =  (4.93 × 10²⁴ Formula Unit × 3 Ions) ÷ 1 Formula Unit

                      X  =  1.48 × 10²⁵ Ions

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.