Respuesta :
1. we want molarity,but first we need to find out moles.
moles KHP = 0.5678g/204.2g
= 2.780X10^-3 mol KHP
2. use stoich to detemine moles of naoh
1 mol KHP= 1 mol NAOH so there are 2.780x10^-3mol NAOH
M= (2.780X10^-3mol NAOH/12.34mL) x (1000L/1L)
M= 0.2254 mol/l
The molarity of the NaOH solution is [tex]\boxed{{\text{0}}{\text{.225 mol/L}}}[/tex].
Further explanation:
Stoichiometry:
It is used to determine the amount of species present in the reaction by the relationship between reactants and products. It is used to determine the moles of a chemical species when moles of other chemical species present in the reaction is given.
Consider the general reaction,
[tex]{\text{A}} + 2{\text{B}} \to 3{\text{C}}[/tex]
Here,
A and B are reactants.
C is the product.
One mole of A reacts with two moles of B to produce three moles of C. The stoichiometric ratio between A and B is 1:2, the stoichiometric ratio between A and C is 1:3 and the stoichiometric ratio between B and C is 2:3.
The reaction between sodium hydroxide and potassium hydrogen phthalate occurs as follows:
[tex]{\text{NaOH}}+{\text{KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}\to{\text{KNa}}{{\text{C}}_{\text{8}}}{{\text{H}}_{\text{4}}}{{\text{O}}_4}+{{\text{H}}_{\text{2}}}{\text{O}}[/tex]
The formula to calculate the moles of [tex]{\text{KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}[/tex] is as follows:
[tex]{\text{Moles of KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4} = \frac{{{\text{Given mass of KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}}}{{{\text{Molar mass of KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}}}[/tex] …… (1)
The given mass of [tex]{\text{KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}[/tex]is 0.5678 g.
The molar mass of [tex]{\text{KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}[/tex]is 204.22 g/mol.
Substitute these values in equation (1).
[tex]\begin{aligned}{\text{Moles of KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}&=\left( {{\text{0}}{\text{.5678 g}}} \right)\left( {\frac{{{\text{1 mol}}}}{{{\text{204}}{\text{.22 g}}}}} \right) \\&=0.00278\;{\text{mol}} \\ \end{aligned}[/tex]
According to the stoichiometry of the reaction, one mole of NaOH combines with one mole of [tex]{\text{KH}}{{\text{C}}_8}{{\text{H}}_4}{{\text{O}}_4}[/tex] to form one mole of [tex]{\text{KNa}}{{\text{C}}_{\text{8}}}{{\text{H}}_{\text{4}}}{{\text{O}}_4}[/tex] and one mole of [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex]. So the number of moles of NaOH is also 0.00278 mol.
Molarity is a concentration term that is defined as the number of moles of solute dissolved in one litre of the solution. It is denoted by M and its unit is mol/L.
The formula to calculate the molarity of the NaOH solution is as follows:
[tex]{\text{Molarity of NaOH solution}} = \frac{{{\text{Moles}}\;{\text{of}}\;{\text{NaOH}}}}{{{\text{Volume }}\left( {\text{L}} \right){\text{ of}}\;{\text{NaOH}}\;{\text{solution}}}}[/tex] …… (2)
Substitute 0.00278 for the moles of NaOH and 12.34 mL for the volume of NaOH solution in equation (2).
[tex]\begin{aligned} {\text{Molarity of NaOH}}&= \left( {{\text{0}}{\text{.00278 mol}}} \right)\left( {\frac{1}{{{\text{12}}{\text{.34 mL}}}}} \right)\left( {\frac{{{\text{1 mL}}}}{{{\text{1}}{{\text{0}}^{ - 3}}\;{\text{L}}}}} \right) \\&={\text{0}}{\text{.2252 mol/L}}\\&\approx {\text{0}}{\text{.225 mol/L}} \\ \end{aligned}[/tex]
So the molarity of NaOH solution is 0.225 mol/L.
Learn more:
1. What is the mass of 1 mole of viruses?: https://brainly.com/question/8353774
2. Determine the moles of water produced: https://brainly.com/question/1405182
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Concentration terms
Keywords: molarity, NaOH, 0.225 mol/L, stoichiometry, potassium hydrogen phthalate, sodium hydroxide, 0.00278 mol, 12.34 mL, molarity of NaOH solution, volume of NAOH, moles of NAOH, KHC8H4O4.
