Question

relation between normality molarity and pH of a solution

Answer 1

THE RELATIONSHIP BETWEEN THE pH VALUE WITH THE MOLARITY OFACID.SCIENTIFIC CONCEPT AND THE CONCEPT OF STRONG ACID AND WEAK ACID.
The pH value for acid can be determine by 2 factor. The factor are:(a) degree of dissociation(b) molarityIn the same molarity, pH of given acid depend on the degree of the dissociationmore highest the degree of dissociation of acid, more lower its pH and more strongest theacid
ExperimentMolarity of HCl (mol dm
-3
)pH value
11.0020.1130.01240.001350.00014 pH can be calculated by using this formula.
pH= 14-pOHpH= -log ( H
+
)
We used this knowledge/ concept of thie equation to find the pH of the acid.
UNIQUE FEATURE OF THIS ACTIVITY.


•
This data can be obtain by replace the value of mol dm
-3
with H
+
into the equation
•
Data displayed in systematic manner, save time in drawing graph, showrelationship of different molarity with pH value.
•
Students will discover that a spreadsheet can be used to process data.
•
Allow student to do more important thing such as analyzing the data on the graph.
TERMINOLOGY.pH
: pH is a measure of the acidity or alkalinity of a solution. Aqueous solutions at 25°Cwith a pH less than seven are considered acidic, while those with a pH greater than sevenare considered basic (alkaline). When a pH level is 7.0, it is defined as 'neutral' at 25°C because at this pH the concentration of H
3
O
+
equals the concentration of OH
−
in purewater. pH is formally dependent upon the activity of hydronium ions (H
3
O
+
),
[1]
but for very dilute solutions, the molarity of H
3
O
+
may be used as a substitute with little loss of accuracy (H
+
is often used as a synonym for H
3
O
+
.) Because pH is dependent on ionicactivity, a property which cannot be measured easily or fully predicted theoretically, it isdifficult to determine an accurate value for the pH of a solution. The pH reading of asolution is usually obtained by comparing unknown solutions to those of known pH, andthere are several ways to do so.
Acid
: An acid (from the Latin acidus meaning sour) is traditionally considered anychemical compound that, when dissolved in water, gives a solution with a hydrogen ionactivity greater than in pure water, i.e. a pH less than 7.0. That approximates the moderndefinition of Johannes Nicolaus Brønsted and Martin Lowry, who independently definedan acid as a compound which donates a hydrogen ion (H+) to another compound (called a base). Common examples include acetic acid (in vinegar) and sulfuric acid (used in car batteries). Acid/base systems are different from redox reactions in that there is no changein oxidation state. Acids can occur in solid, liquid or gaseous form, depending on thetemperature. They can exist as pure substances or in solution.


Weak acid:
Only partially dissociates in aqueos solution and therefore exist in thesolution as mixture of acid molecule and and their constituent ions. The conjugateconjugate base of weak acid show a slight ability to remove proton from water.(Theconjugate base of a weak acid is a weak base)
Strong acid
: completely transfer its proton to water, leaving no undissociated moleculein the solution. Its conjugate base has a negligible tendency to be protonated ( to abstract proton) in aqueous solution.
Molarity
: Molarity (M/ dm
-3
) express the concentration of a solution as the number of moles of solute in a liter solution
Hope this helps u