Answer:
they require more testing in real-word conditions
Explanation:
One of the biggest reasons for this very slow uptake of hydrogen vehicles is the existing infrastructure. ... The sceptics' first argument against hydrogen vehicles is that they're less efficient than EVs are. Because hydrogen doesn't occur naturally, it has to be extracted, then compressed in fuel tanks.
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