You can start by writing out the molecular formula of each molecule.
Aluminum (Al 3+) Phosphate (PO4 3-)
AlPO4
Nickel II (Ni 2+) sulfide (S 2-)
NiS
Aluminum Sulfide
Al2S3
Nickel Phosphate
Ni3(PO4)2
If you’re wondering, we get those charges by looking at the periodic table. The metals usually have a + charge based on their group number. The nonmetals usually - charge egual to 8 - their group number.
You then balance the ions by flipping the charges, dropping the signs, and adding them in as subscripts.
Now we can put it into an equation
AlPO4 + NiS —-> Al2S3 + Ni3(PO4)2
Balance by adding coefficients
2 AlPO4 + 3 NiS —-> Al2S3 + Ni3(PO4)2
I think the correct answer among the choices presented above is option A. An ore is rock that contains a mineral or metal with economic usefulness. Examples are copper ore, gold ore and iron ore. These ores are being extracted from the Earth by mining.
Answer:
i am sure its the last one
Solid KMnO₄ needed = 7.9 g
<h3>Further explanation</h3>
Given
MW KMnO₄ = 158 g/mol
500 mL(0.5 L) of a 0.1M stock solution of KMnO₄
Required
solid KMnO₄
Solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution

Input the value :
n = M x V
n = 0.1 M x 0.5 L
n = 0.05 mol
Mass KMnO₄ :
= mol x MW
= 0.05 x 158 g/mol
= 7.9 g