Two [hydrogen] atoms and one [oxygen] atom
Answer:
Ammonia > Urea > Ammonium nitrate > Ammonium sulphate
Explanation:
Percentage by mass of nitrogen in NH3:
Molar mass of NH3= 17 g/mol
Hence % by mass = 14/17 × 100 = 82.35%
% by mass of NH4NO3
Molar mass of NH4NO3 = 80.043 g/mol
Hence; 28/80.043 × 100 = 34.98%
% by mass of (NH4)2SO4;
Molar mass of (NH4)2SO4= 132.14 g/mol
Hence; 28/132.14 × 100 = 21.19%
% by mass of CH4N2O
Molar mass of urea = 60.0553 g/mol
Hence 28/60.0553 × 100 = 46.62%
The pressure of the gas = 40 atm
<h3>Further explanation</h3>
Given
200 ml container
P = 2 atm
final volume = 10 ml
Required
Final pressure
Solution
Boyle's Law
At a fixed temperature, the gas volume is inversely proportional to the pressure applied

Input the value :
P₂ = P₁V₁/V₂
P₂ = 2 x 200 / 10
P₂ = 40 atm
The reaction of acid, assuming HCl and calcium carbonate always produces a gas. The reaction is as follows:
2 HCl + CaCO3 --> CaCl2 + H2CO3
H2CO3, carbonic acid, is a weak acid that is unstable in water solutions at high concentrations. As such, it decomposes:
H2CO3 --> H2O + CO2
Then,
2 HCl + CaCO3 --> CaCl2 + H2O + CO2
The total ionic equation looks as follows:
2H+(aq) + 2 Cl-(aq) + CaCO3(s) --> Ca+2(aq) + 2 Cl-(aq) + H2O(l) + CO2(g)
Clearly, Cl- is a spectator ion as it is unchanged in the reaction. The net ionic reaction looks as follows:
2 H+(aq) + CaCO3(s) --> Ca+2(aq) + H2O(l) + CO2(g)