Answer:
Mass of oxygen in glucose = 29.3g 
Explanation:
Mass of glucose given is 55grams. 
We are to find the mass of oxygen in this compound. 
In the compound we have 6 atoms of oxygen. 
Solution
To find the mass of oxygen in glucose, we calculate the formula mass of glucose. We now divide the formula mass of the oxygen atom with that of the glucose and multiply by the given mass to find the unkown mass. 
Atomic mass of C = 12g
                            H = 1g
                            O = 16g 
Formula mass of C₆H₁₂O₆ = {(12x6) + (1x12) + (16x6)} = 180
              Mass of O in glucose =  x 55
  x 55
                                                   =  x 55
 x 55
                                                   = 0.53 x 55
             Mass of oxygen in glucose = 29.3g 
 
        
             
        
        
        
I believe the most massive element that is naturally occurring on Earth is uranium (U), which has a nucleus of 92 protons 
 
        
             
        
        
        
Solution:
At the equivalence point, moles NaOH = moles benzoic acid  
HA + NaOH ==> NaA + H2O where HA is benzoic acid  
At the equivalence point, all the benzoic acid ==> sodium benzoate  
A^- + H2O ==> HA + OH- (again, A^- is the benzoate anion and HA is the weak acid benzoic acid)  
Kb for benzoate = 1x10^-14/4.5x10^-4 = 2.22x10^-11  
Kb = 2.22x10^-11 = [HA][OH-][A^-] = (x)(x)/0.150  
x^2 = 3.33x10^-12  
x = 1.8x10^-6 = [OH-]  
pOH = -log [OH-] = 5.74  
pH = 14 - pOH = 8.26  
 
        
                    
             
        
        
        
Answer:
 C nhé ! CH3COOH là axit chứ không phải este