Química Geral ⇒ (Unitau-SP) Constante Avogadro Tópico resolvido

[gabrielifce]

Qual a massa em gramas de uma molécula de açúcar comum ou sacarose ,C(12)H(22)O(11)?
Dados:C=12 u; H=1 u e O=16 u.
Constante de Avogadro=6,02.[tex3]10^{23}[/tex3]
a)5,68.[tex3]10^{-22}[/tex3] g
b)6,02.[tex3]10^{23}[/tex3] g
c)342g
d)5,68.[tex3]10^{-23}[/tex3] g
e)3,42.[tex3]10^{-21}[/tex3] g
Resp item A

[theblackmamba]

A massa da sacarose vale: [tex3]12\cdot 12+22\cdot 1+11\cdot 16=324\text{g}[/tex3]

[tex3]1\text{mol} \rightarrow 342g \rightarrow 6,02 \cdot 10^{23}\,\text{moleculas}[/tex3]
[tex3]\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,x\rightarrow 1\,\text{molecula}[/tex3]

[tex3]x=\frac{342}{6,02 \cdot 10^{23}}[/tex3]
[tex3]x\approx 56,81 \cdot 10^{-23}\,\text{g}[/tex3]
[tex3]\boxed{x\approx 5,681 \cdot 10^{-22}\,\text{g}}[/tex3]. Letra A