Answer:
Mass of sodium hydroxide needed  = 28.2 g
Explanation:
Given data:
Mass of sodium hydroxide = 80 g
Mass of sodium sulfate produced = 142 g
Mass of sodium hydroxide needed = ?
Mass of sodium sulfate produced = 50 g
Solution:
Mass of sodium sulfate produced / Mass of sodium hydroxide = Mass of sodium sulfate produced / x
142 g/ 80 g = 50 g / x 
x = 50 g × 80 g / 142 g
x =4000 g/ 142
x = 28.2 g
 
        
             
        
        
        
Answer:
(1) Bromination, (2) E2 elimination and (3) epoxidation
Explanation:
- In the first step, -OH group in cyclopentanol is replaced by more facile leaving group Br by treating cyclopentanol with  
- In the second step, E2 elimination in presence of strong base e.g. NaOEt/EtOH produce cyclopentene
- In the third step, treatment of cyclopentene with mCPBA produces 1,2-epoxycyclopentane
- Full reaction scheme has been shown below
 
        
             
        
        
        
Answer: The pH 0f 0.10 solution of HCl is 1.00
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D) 
 
According to stoichiometry,  
1 mole of  gives 1 mole of
 gives 1 mole of  
  
Thus  moles of
 moles of  gives =
 gives = moles of
 moles of  
  
Putting in the values:
![pH=-\log[0.10]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5B0.10%5D) 
 
Thus pH 0f 0.10 solution of HCl is 1.00
 
        
             
        
        
        
Answer:
It gives the number of protons in the nucleus of each atom of that element. 
Explanation:
 
        
             
        
        
        
The balanced chemical reaction describing this decomposition is as follows:
<span>4c3h5n3o9 .............> 6N2 + 12CO2 +10H2O + O2
From the periodic table:
mass of oxygen = 16 grams
mass of nitrogen = 14 grams
mass of hydrogen = 1 gram
mass of carbon = 12 grams
Therefore:
mass of </span><span>C3H5N3O9 = 3(12) + 5(1) + 3(14) + 9(16) = 227 grams
mass of O2 = 2(16) = 32 grams
From the balanced chemical equation:
4(227) = 908 grams of </span>C3H5N3O9 produce 32 grams of O2. Therefore, to know the amount of oxygen produced from 4.5*10^2 grams <span>C3H5N3O9, all we need to do is cross multiplication as follows:
amount of oxygen = (4.5*10^2*32) / (908) = 15.859 grams</span>