Answer:
Mass of liquid: 20.421g
Density= 1.0109405940594 g/mL
Explanation:
Mass of liquid
To find mass of liquid you take the mass of beaker + liquid (171.223g) and subtract it from the Mass of beaker (beaker without the water). The difference is the answer.
171.223g - 150.802g = 20.421g
Density
To find density you use the formula Mass/Volume. Take the Volume given, and the mass of the liquid you just found.
20.421mL/20.421g = 1.0109405940594 g/mL
Balanced Equation is
4H2SiCl2+4H2O → H8Si4O4 + 8HCl
For Iron:

For Oxygen:

These are the two chemical symbols for the two elements found in Iron Oxide.
A catalyst is when a chemical reaction occurs faster than normal.
The system is unaffected during a catalyst because both forward and reverse reactions are affected, meaning that quilibrium will occur faster nothing will change.
Hope it helped,
BioTeacher101