A precipitate will form since BaSO₄ is insoluble in water.
Answer:
The correct answer is option D.
Explanation:
A fuel cell is defined as the electrochemical cell which converts the chemical energy of a fuel (often used hydrogen) and an oxidizing agent (often used oxygen) into electrical energy via a pair of redox reactions.
The reactions which occur in hydrogen-oxygen fuel cell are:
At cathode: 
At anode: 
As we can see that reaction of hydrogen gas with oxygen gas gives us the water as a product which can be used for other things and it also doesn't pollutes environment.
Based on Hess's Law:
<span>2 N2(g) + 6 O2(g) + 2 H2(g) −→ 4 HNO3(l) ∆Hf = (−171.9 kJ/mol)(4 mol) </span>
<span>2 H2O(l) −→ 2 H2(g) + O2(g) ∆Hf = (-283.8 kJ/mol)(2 mol)(-1) →times -1, rxn is reversed </span>
<span>4 HNO3(l)−→ 2 N2O5(g) + 2 H2O(l) ∆Hf = (-76.4 kJ/mol)(2 mol)(-1) →times -1, rxn is reversed </span>
<span>2 N2(g) + 5 O2(g) −→ 2 N2O5(g) ∆H0 = 32.8 kJ</span>
Methane is CH4
Ethane is. C2H6
Method by ☆cracking alkanes☆
In this case, by cracking methane
Cracking alkanes is the method used to split a long alkane structure into smaller alkanes using high temperature and a catalyst.
e.g. C2H6 -> CH4 + CH2
M(NH₃)=51g, n(NH₃)=m/M=51g÷17g/mol(14+3×1)=3mol
N(NH₃)=n×Na(Avogadro number)=3mol×6·10²³1/mol=18×10²³ molecules
