Question

Vamos à atividade:
1- Calcule o valor do mol ( massa molar ) dos seguintes compostos:
a- NaOH
b- CaNO3
c- Al2 (SO4)3
d- H2CO3
2- Qual a massa que corresponde a:
a- 2 mols de NaCl
b- 0,5 mol de KOH
c- 0,6 mol de Na2CO3
d- 0,1 mol de H2SO3

Answer 1

Olá!:

1 )

a) NaOH =  ( 23 * 1 ) + ( 16 * 1 ) +( 1 * 1 ) => 40 g/mol

b) Ca(NO₃)₂ =  ( 40 * 1 ) + ( 14 * 2 ) + ( 16 * 6 ) => 164 g/mol

c) Al₂(SO₄)₃ = (  27 *2 )+ ( 32 * 3 ) + ( 16 * 12 ) => 342 g/mol

d ) H₂CO₃ = ( 1 * 2 ) + ( 12 * 1 ) + ( 16 * 3 ) => 62 g/mol

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2)

a) Massa molar NaCl = ( 23 * 1 ) + ( 35,5 * 1 ) => 58,5 g/mol

1 mol NaCl -------------- 58,5 g

2 mol --------------------- m

m = 2 * 58,5 / 1

m =  117 g

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b)  Massa molar KOH = ( 39 * 1 ) + ( 16 * 1 ) + ( 1 * 1 ) => 56 g/mol

1 mol KOH -----------------  56 g

0,5 mols -------------------- m

m = 0,5 * 56 / 1

m = 28 g

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c) Massa molar Na₂CO₃ = ( 23 * 2 ) + ( 12 * 1 ) + ( 16 * 3 ) => 106 g/mol

1 mol Na₂CO₃ ----------------------- 106 g

0,6 mols ----------------------------- m

m = 0,6 * 106 / 1

m = 63,6 g

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d) Massa molar H₂SO₃ = ( 1 * 2 ) + ( 32 * 1 ) + ( 16 * 3 ) => 82 g/mol

1 mol H₂SO₃ ----------------------- 82 g

0,1 mol ----------------------------- m

m = 0,1 * 82 / 1

m = 8,2 g

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Espero ter ajudado!