The balanced chemical reaction would be:
FeS(s)+2HCl(aq)→FeCl2(s)+H2S(g) 
We are given the amount of the reactants to be used for the reaction. We use these amounts. First, we determine the limiting reactant of the reaction. From the data, we can say that FeS is the limiting ad HCl is the excess reactant. We calculate as follows:
Amount of HCl used: 0.240 mol FeS x 2 mol HCl / 1 mol FeS = 0.48 mol HCl
0.646 - 0.48 = 0.166 mol HCl left
        
                    
             
        
        
        
During a phenomenon called beta decay the neutron of the isotope uranium 237 emits/releases an electron causing an increase of atomic number. With the reference of a periodic table the "new" element is Neptunium or Np-237. 
        
             
        
        
        
Answer:
HF
Explanation:
Hf has hydrogen bonding which is the strongest intermolecular forces. The stronger the IM forces, the higher the boiling point. 
 
        
             
        
        
        
Answer: Too much base was added 
i guessed
Explanation:
 
        
             
        
        
        
Answer:
poop
Explanation:
poopy sorry needed points.