Answer:
I beleve it would be -3 or -2
Explanation:
 
        
             
        
        
        
Answer:
3.01  x 10²¹
Explanation:
Molar mass of h₂o =18.01528 g/mol. 
it means 1 mole h₂o=18.01528 g .....(1)
1 mole = 6.022 × 10^23 molecules
so, 
1 mole  h₂o =6.022 × 10^23 molecules=18.01528 g  [from 01]
now,
18.01528 g h₂o has= 6.022 × 10^23 molecules
9.00x10⁻² g h₂o has= ( 6.022 × 10^23 x 9.00x10⁻² ) /18.01528 molecules
                                   =3.008 x 10²¹ molecules
                                   ≈ 3.01  x 10²¹ molecules
 
        
                    
             
        
        
        
<span>When calcium hydroxide dissolves, it dissociates into
Ca(OH)2 = Ca2+ and 2OH-
Let's assign the variable X for the solubility of Ca2+ and OH
I.e Ca2+ = X and 2OH- = 2X
Then Ksp = [Ca2+][OH-]^2
So we have (X) (2X)^2 = 5.02 * 10^(-6)
4X^3 = 5.02 * 10 ^(-6)
X^3 = 5.02 * 10^(-6) / 4
X^3 = 0.003110
X = 0.1459</span>
        
             
        
        
        
Answer:
i = 2.79
Explanation:
The excersise talks about the colligative property, freezing point depression.
Formula to calculate the freezing point of a solution is:
Freezing point of pure solvent - Freezing point of solution = m . Kf . i
Let's replace data given. (i = Van't Hoff factor, numbers of ions dissolved in solution)
48.1°C - 44°C = 0.15 m . 9.78°C/m . i
4.1°C / (0.15 m . 9.78°C/m) = i
i = 2.79
In this case, numbers of ions dissolved can decrease the freezing point of a solution, which is always lower than pure solvent. 
 
        
             
        
        
        
Answer:
atomic mass. You will have created an isotope.
Explanation: