3. ÇEVRE DOSTU ÜRÜN PAZARI İLE İLİŞKİLİ TEMEL KAVRAMLAR
3.4. Sürdürülebilir(Çevreci) Tüketim Davranışı
A figura A.1.1. ilustra uma representação da rede cristalina do SnO2 utilizando esferas e
hastes.
Figura A.1.1.- Representação da rede cristalina do SnO2.94
A tabela A.1.1. abaixo apresenta algumas propriedades físicas e químicas do SnO2. Tabela A.1.1.- Propriedades físicas e químicas do SnO2.
SnO2 Descrição e Valores da Propriedade
Fórmula comumente escrita SnO2
Fórmula no sistema de Hill O2Sn1
Número de registro CAS [18282-10-5]
Massa Molar 150,709 g.mol-1
Classe Óxido
Cor Branco ou Cinza
Aparência Sólido cristalino
Ponto de Fusão 1630°C
Ponto de vaporização 1900°C
Densidade 6900 kg m-3
Constituintes % Estado de Oxidação Configuração
Eletrônica
O 21,23 -2 [He].2s2.2p6
Sn 78,77 +4 [Kr].4d10
O dióxido de estanho é um semicondutor do tipo n. Isto significa que a condução elétrica deste material é devido ao fluxo de elétrons. O SnO2 apresenta este comportamento porque é um
material não estequiométrico que contém vacâncias de oxigênio. Para que a neutralidade elétrica seja mantida, as espécies de oxigênio O2- saem do SnO2 como espécies O neutras deixando elétrons
nas vacâncias de oxigênio.
A tabela A.1.2 apresenta algumas características cristalográficas do dióxido de estanho.95
Tabela A.1.2. – Características cristalográficas do SnO2.
Ficha ICSD #90611
Código de Coll 90611
Data da ficha 18/12/2001
Nome Dióxido de estanho
Estrutura Sn O2
Nome do mineral Cassiterita
Cela unitária 4,7350(3) Å 4,7350(3) Å 3,1837(2) Å 90º 90º 90º
Volume 71,38 Å3
Z 2
Grupo espacial P 42/m n m
Número do grupo espacial 136
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