[DQD]

I have question about it

when we do the reaction with catalyst. will it be changed about its form ?
For Example: the catalyst is silicon dioxide (such as a cube glass) - $$SiO_2 /$$
After reacting, Is it still a cube or will be changed to another form ?

And Does Lead Sulfide react with Sodium Hypochlorite ?
$$ PbS + NaClO = /$$ 

[Nobby]

catalyst only accelarate an chemical reaction. The material will be the same after the reaction took place.

Lead sulfide and Hypochlorite. I guess yes, although PbS has bad solubility.

[DQD]

can you write the Chemical Equations of this reaction ?

by the way, why can't i use Latex 

[Borek]

Most likely sulfide gets oxidized to sulfate, while hypochlorite gets reduced to chloride.

LaTeX works, but usage is quirky.