Calculate first the number of moles of ethylene glycol by dividing the mass by the molar mass.
                           n = (6.21 g ethylene glycol) / 62.1 g/mol
                              n = 0.1 mol
Then, calculate the molality by dividing the number of moles by the mass of water (in kg).
                           m = 0.1 mol/ (0.025 kg) = 4m
Then, use the equation,
                       Tb,f = Tb,i + (kb)(m)
Substituting the known values,
                       Tb,f = 100°C + (0.512°C.kg/mol)(4 mol/kg)
                          <em>Tb,f = 102.048°C</em>
        
                    
             
        
        
        
I believe your answer would be the first one
hope this helps
        
                    
             
        
        
        
Producer. Hope this helps!
        
             
        
        
        
Hey there! 
Answer: Protons 
The atom in a sample of an element must contain nuclei with the same number of protons. If the protons change in number, then the element will modify as well. 
Thank you!
        
             
        
        
        
Answer:
398 mL
Explanation:
Using the equation for molarity,
C₁V₁ = C₂V₂ where C₁ = concentration before adding water = 8.61 mol/L and V₁ = volume before adding water, C₂ = concentration after adding water = 1.75 mol/L and V₂ = volume after adding water = 500 mL = 0.5 L
V₂ = V₁ + V' where V' = volume of water added.
So, From C₁V₁ = C₂V₂
V₁ =  C₂V₂/C₁ 
= 1.75 mol/L × 0.5 L ÷ 8.61 mol/L 
= 0.875 mol/8.61 mol/L 
= 0.102 L
So, V₂ = V₁ + V'
0.5 L = 0.102 L + V'
V' = 0.5 L - 0.102 L 
= 0.398 L 
= 398 mL
So, we need to add 398 mL of water to the nitric solution.