Answer:
thats all help me too:)...............
 
        
             
        
        
        
Alkanes are saturated hydrocarbon, that is they contain hydrogen and carbon without a double or triple bond between the carbon atoms, e.g. ethane, propane. Group 7a in the periodic table are called halogens e.g chlorine, bromine. Alkanes react with halogens in a reaction called substitution, where halogens replace hydrogen atoms in alkanes.
        
                    
             
        
        
        
Answer:
B. Equal to 7.
Explanation:
Hydrobromic acid is a strong acid that decreases pH and ammonia is a strong base that increases pH.
As the initial pH of water is 7,0 the addition of 35.0mL of 0.400M HBr will produce a pH less than 7,0. But, the same effect of decreasing pH is reverted for the addition of 35.0mL of 0.400M HNO3. 
That means the net effect of the two addition is to have a pH:
B. Equal to 7.
I hope it helps!
 
        
             
        
        
        
Answer:
See explanation and image attached
Explanation:
Fischer esterification is a type of reaction used  to convert carboxylic acids to ester in the presence of excess alcohol and a strong acid which acts as a catalyst. Another final product formed in the reaction is water. 
The mechanism for the fischer esterification of Benzoic acid and  C H 3 O H in the presence of HCl as the catalyst is shown in the image attached to this answer.
The final products of the reaction are methyl benzoate, water and H^+ as shown in the image attached.
 
        
             
        
        
        
According to the law of conservation of mass, the mass of reactants will be equal to the mass of the products. The mass of products and reactants will only differ during a nuckear reaction
Changing of the physical state of water is not a nuclear reaction. So becoz of that the mass will remain constant without any change.