How many molecules of oxygen atoms are contained in the 2.50 mol K2Cr2O7
Answers
Atomicity —— number of total atoms present in a compound
no. of atoms = atomicity × moles × 6.022×10^23
no. of atoms = (2+2+7) × 0.5 × 6.022 × 10^23
no.of atoms = 11 × 0.5 × 6.022 × 10^23
no.of atoms = 33.121 × 10^23
no.of atoms = 3.3121 × 10^24
So there are 3.3121 × 10^24 atoms in K2Cr2O7
If we are finding the number of oxygen (O) in given compound we take atomicity as a ‘7′ because there are 7 oxygen atoms present . Then fill values in formula to find number of oxygen atoms in K2Cr2O7 .And for other elment i.e Cr or K also follows same rules.
How to find the number of molecules present in a compound ? We know that 1 mole of any substance contain avogadro (6.022×10^23) molecules.Then 'n' moles of any substance contains “ n×6.022×10^23 ” molecules.
No. of molecules = number of moles × 6.022×10^23 molecules.
How to find the volume of the compound if numbers of moles are givine ?we know that 1 mole of any substances contains “ 22.7 liter ” at S.T.P(Standard Temperature and Pressure i.e Temperature = 0°C and pressure = 1bar ) then ' n ' moles of any substance contains “ n×22.7 l ” volume.i.e
Volume = number of moles × 22.7 l