Answer:
3.11 mol/kg
Explanation:
Molality M = number of moles of solute, n/mass of solvent, m
To calculate the number of moles of glycerol (C₃H₈O₃) in 22.75 g of glycerol, we find its molar (molecular) mass, M',
So, M' = 3 × atomic mass of carbon + 8 × atomic mass hydrogen + 3 × atomic mass of oxygen
= 3 × 12 g/mol + 8 × 1 g/mol + 3 × 16 g/mol = 36 g/mol + 8 g/mol + 48 g/mol = 92 g/mol.
So, number of moles of glycerol, n = m'/M' where m' = mass of glycerol = 22.75 g and M' = molecular mass of glycerol = 92 g/mol
So, n = m'/M'
n = 22.75 g/92 g/mol
n = 0.247 mol
So, the molality of the solution M = n/m
Since m = mass of ethanol = 79.6 g = 0.0796 kg, substituting the value of n into the equation, we have
M = 0.247 mol/0.0796 kg
M = 3.11 mol/kg
So, the molality of the solution is 3.11 mol/kg.
repeat the experiment would be the easiest way to make sure u got the correct and accurate answer
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.
I believe such reactions are called decomposition reactions. Decomposition reactions are reactions that involve breaking down a compound into smaller compounds or individual elements. They involve input of energy in the form of heat, electricity or light to break down the compounds. When light is used the reaction is referred to as photo decomposition while when heat is used the reaction is thermal decomposition reaction e.t.c. The general form of the reaction is AB = A + B.
