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Physical Chemistry

The number of unit cells in 58.5 gram of sodium chloride is nearly
a)6*1020 b)3*1022 c)1.5*1023 d)0.5*10^24

Profile image of Apeksha Bhaskar Vyas
8 Years agoGrade
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1 Answer

Profile image of Arun
8 Years ago
as you know that in NaCl, Cl ions forms Fcc and Na ions occupy octahedral voids. 
The formula unit cell is 4 i.e. 1 unit cell of NaCl contains 4 NaCl particles. 
58.5 gm of NaCl contains-6.022*10^23 atoms 
 
4 atoms constitute 1 unit cell 
therefore, 6.022*10^23 atoms constitute 6.022*10^23/4 
 
 = 1.5 * 10^23
 
 
Regards
Arun (askIITians forum expert)