W(Cl)=0.3877
w(O)=0.6123
M(Cl)=35.5 g/mol
M(O)=16.0 g/mol
ClₐOₓ
M(ClₐOₓ)=35.5a+16.0x
w(Cl)=35.5a/(35.5a+16.0x)
w(O)=16.0x/(35.5a+16.0x)
solve a system of two equations with two unknowns
35.5a/(35.5a+16.0x)=0.3877
16.0x/(35.5a+16.0x)=0.6123
a=2
x=7
Cl₂O₇ is the empirical formula
Plasma has a neutral charge, as well as the same amount of protons and electrons put together. if the question has only one answer then it is plasma.
Answer: (D) 0.025 mol 
Explanation:
The given balanced equation is :
According to stoichiometry :
4 moles of ammonia 
reacts with = 5 moles of oxygen 
Thus 0.30 moles of ammonia reacts with = 
moles of oxygen
Now as given moles of oxygen are more than the required amount, oxygen is the excess reagent.
moles of oxygen left = 0.40 - 0.375 = 0.025
Thus 0.025 mol excess reagent remains.
Combination reaction. Two or more substances react to form a single substance.
