Answer:
B. CdSO4(aq) + K2S(aq) → CdS(s) + K2SO4(aq)
Explanation:
A precipitate reaction is when a solid forms, so in this case CdS is the precipitate. 
 
        
             
        
        
        
Explanation:
                           NH₄F+     AICI₃,    →   NH₄CI +   AlF₃
    NH,F: in ionic form
            NH₄⁺ + F⁻   =    NH₄F
    AICI in ionic form: 
          Al³⁺ + Cl⁻   = AlCl₃
    NH Cl in ionic form: 
           NH₄⁺ + Cl⁻ = NH₄Cl 
     Al F in ionic form: 
          Al³⁺ + F⁻   =  AlF₃
                      NH₄F+     AICI₃,    →   NH₄CI +   AlF₃
Now we have to balance the equation with respect to the atoms: 
            aNH₄F+     bAICI₃,    →   cNH₄CI +   dAlF₃
   for N: a = c
         H: 4a = 4c 
         F:  a = 3d 
         Cl: 3b = c
    let a = 1
         c = 1 
          b = 
         d = 
Therefore we can imply that: 
      a = 3, b = 1 , c = 3 and d = 1 if we multiply through by 3
            3NH₄F+     AICI₃,    →   3NH₄CI +   AlF₃
Learn more: 
Chemical equation brainly.com/question/2924195
#learnwithBrainly
  
 
        
             
        
        
        
Answer:
Explanation:
Deal with 1 mole first.
The chemical formula of Magnesium Phosphate is
Mg3(PO4)2
The 2 tells you that there are 2 mols of Phosphorus in the chemical.
1 mol of anything is 6.02 * 10^23 (in this case) atoms.
2 mols of anything is 12.04 * 10^23 atoms
2 moles of anything is 1.204 * 10^24 (the 2 answers are the same. This one is more correct in scientific notation.)
Now we come to the 5.01. Where does that go?
5.01 * Mg3(PO4)2
So multiply 1.204 * 10^24 by 5.01 When you do, you get 
7.26 * 10^24 atoms
 
        
             
        
        
        
Are you trying to find density? if so divide 108g by 12cm3 which is 9g/cm3