You're right to notice the difference in hydrolysis resistance between carbon and silicon compounds. Here's why CH4 and CCl4 are more resistant to hydrolysis than their silicon counterparts:

1. Bond Strength:

* Carbon-Hydrogen (C-H) and Carbon-Chlorine (C-Cl) Bonds: These bonds are significantly stronger than their silicon counterparts (Si-H and Si-Cl). This is due to the smaller size of the carbon atom compared to silicon, leading to greater orbital overlap and stronger covalent bonds.
* Silicon-Hydrogen (Si-H) and Silicon-Chlorine (Si-Cl) Bonds: These bonds are weaker due to the larger size of silicon and less effective orbital overlap. This makes them more susceptible to attack by water molecules.

2. Polarity and Reactivity:

* carbono: The C-H and C-Cl bonds are relatively nonpolar, making them less reactive towards polar water molecules.
* silício: Si-H and Si-Cl bonds are more polar due to the electronegativity difference between silicon and the other elements. This polarity makes them more susceptible to nucleophilic attack by water.

3. Steric Effects:

* carbono: O tamanho menor dos átomos de carbono permite um impedimento menos estérico, dificultando a abordagem das moléculas de água e atacam as ligações C-H e C-Cl.
* silício: The larger size of silicon atoms creates more steric hindrance, allowing water molecules easier access to the Si-H and Si-Cl bonds.

Hydrolysis Reaction:

Hydrolysis reactions involve the breaking of a bond by the addition of water molecules. For example, in the case of silicon compounds:

* Si-Cl + H2O-> Si-OH + HCl

A ligação SI-CL enfraquecida é mais suscetível ao ataque pela água, levando à formação de um grupo SI-OH (silanol) e HCl.

Resumo:

A combinação de ligações mais fortes, menor polaridade e menos impedimento estérico em compostos de carbono como CH4 e CCL4 os torna mais resistentes à hidrólise em comparação com seus análogos de silício.