Answer:
sulfur will form an ion with negative charge
 
        
             
        
        
        
I think this is how you do it:
 
        
        
        
Answer:
5.36 grams the mass in grams of zinc nitrate the chemist has added to the flask. 
Explanation:

Moles of zinc nitrate = n 
Volume of the solution = 135.0 mL = 0.1350 L
Molarity of the solution = 0.21 M


Mass of 0.02835 moles of zinc nitrate:
0.02835 mol × 189 g/mol = 5.358 g ≈ 5.36 g
5.36 grams the mass in grams of zinc nitrate the chemist has added to the flask. 
 
        
             
        
        
        
<em>Answer:</em>
- Conc. of K+ ions = 0.90 M
- Coc. of SO4∧-2 = 0.45 M
<em>Explanation:</em>
<em>Data Given:</em>
 Conc. of H2SO4 = 0.450
As sulphoric acid is a strong electrolyte, it completely dissociate into ions.
H2SO4 ⇆   2K+   +   SO4∧-2
.450 M K2SO4 means that there is .450 mols of K2SO4 in every liter of solution.
                       K2SO4  :  K+                                          K2SO4  : SO4∧-2
                           1      =     2                                                   1     =    1
                      0.450   =   2× 0.450 = 0.90                     0.450 =  0.450×1 = 0.450
<em> Result:</em>
 Conc. of potassium ion will be 0.90M     
Coc. of sulphate ions will be 0.45 M