Ideal gas law is a combination of three gas laws, which are Boyle's law, Charles' law and Avogadro's law. Ideal gas law states that PV = nRT, where:
P = pressure of the gas
V = volume of the gas
n = no of moles of the gas
R = universal gas constant
T = absolute temperature in Kelvin
        
                    
             
        
        
        
Explanation:
The reaction given is;
TiCl4 + H2O --> TiO2 + HCl
The reaction is not balanced, upon balancing it is given as;
TiCl4 + 2H2O → TiO2 + 4HCl  
a. How many moles of H2O are needed to react with 6.50 moles of TiCl4? 
From the reaction;
1 mol of TiCl4 requires 2 mol of H2O
6.50 mol of TiCl4 would require x mol of H2O
1 = 2
6.5 = x
x = 6.5 * 2 / 1 = 13.0 mol
b. How many moles of HCl are formed when 8.44 moles of TiCl4 react?
From the equation of the reaction;
1 mol of TiCl4 reacts to form 4 mol of HCl
8.44 mol of TiCl4 reacts to form x mol of HCl
1 = 4
8.44 = x
x = 8.44 * 4 / 1 = 33.76 mol
 
        
             
        
        
        
Answer:
Bacterial cell, cell with a nucleus, multicellular organism