The hydrogen ion concentration, [H ], in the solution of phenol red solution of pH 11.20 is 6.3 X 
moles/litre.
Explanation:
Data given:
basic solution of phenol red is given as it has pH of 11.2
hydrogen ion concentration = ?
the hydrogen ion concentration is calculated by using the following formula:
pH = -
[
]
Rearranging the equation:
[] = 
Putting the values in the above equation:
[] = 
[] = 6.3 X moles/litre
The hydrogen ion concentration is very small and the solution of phenol red is basic in nature. The pH of 11.2 also indicates that solution is basic and teh color of the solution is bright pink.
Oxygen's atomic weight is 16.00 amu. 1 mole of oxygen is 6.02 x 1023 atoms of oxygen 1 amu = 1.661 x 10-24g What is the molar mass (g/mole) of oxygen? Molar mass (in grams) is always equal to the atomic weight of the atom! Molar mass (in grams) is always equal to the atomic weight of the atom!
Changes in energy and formation of new substances.
The reaction to form NH3 is : N2 + 3H2-> 2NH3 12,33g NH3 is 12,33/17,03=0,3 =0,724 moles of NH3 moles NH3. So you need 1,5*0,724 = 1,086 moles H2 1,086*2,016 = 2,189 g of H2 is needed ro form 12,33 g NH3
