PCl5 0.2 mol Fe2O3 80 g CO 3.0×10^21

PCl5 0.2 mol Fe2O3 80 g CO 3.0×10^21

 

 

Without doing any detailed calculations

(but using a periodic table to give atomic weights),

rank the following samples

in order of increasing numbers of atoms:

0.2 mol PCl5 molecules,

80 g Fe2O3,

3.0×10^21 CO molecules.

 

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▶ 참고: 아보가드로수와 몰(mol)

[ https://ywpop.tistory.com/6475 ]

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① 0.2 mol PCl5 molecules

분자 mol수 × 원자 개수 × N

= 0.2 mol × 6 × (6.022×10^23 개/mol)

= 0.2 × 6 × (6.022×10^23)

= 7.2×10^23 atoms

 

 

 

② 80 g Fe2O3

Fe2O3의 몰질량 = 159.69 g/mol 이므로,

80 g × (1 mol / 159.69 g) = 0.50 mol Fe2O3

( 참고 https://ywpop.tistory.com/7738 )

 

분자 × 원자 × N

= 0.50 × 5 × (6.022×10^23)

= 1.5×10^24 atoms

 

 

 

③ 3.0×10^21 CO molecules

(3.0×10^21) × 2

= 6.0×10^21 atoms

 

 

 

답: ③ < ① < ②

 

 

 

 

[키워드] 원자의 개수 기준문서