Chemistry Titration

Question 1

When we get concentration of product which V should we use ?

Answer 1

Vtotal

Question 2

Define equivalence (quantitatively)

Answer 2

At equivalence,reactants are present in stioichiometric proportions

Question 3

Define equivalence (qualitatively)

Answer 3

Equivalence is detected by the first drop of titrant that leaves a permanent change in the color of the solution on the beaker from (color) to ( color)

Question 4

Species present in the solution: initially

Answer 4

●(analyte)
●H+(acidic medium)
●H²O(solvent)
●(spectator ion)

Question 5

Species present in the solution: before equivalence

Answer 5

●(analyte)
●(spectator)
●(spectator)
●H+(acidic medium)
●H²O (solvent)
●(product)
●(product)

Question 6

Species present in the solution: at equivalence

Answer 6

●(spectator)
●(spectator)
●H+(acidic medium)
●H²O(Solvent)
●(product)
●(product)

Question 7

Species present in the solution: after equivalence

Answer 7

●(titrant in excess)
●(spectator)
●(spectator)
●H+(acidic medium)
●H²O(solvent)
●(product)
●(product)

Question 8

Glassware

Answer 8

●—ml volumetric flask to prepare S1
●—ml graduated pipet (if decimal) or volumetric pipet to take V0
●100 ml beaker to avoid contamination of S0

Question 9

Why do we do dilution before titration ?

Answer 9

Because the solution we are titrating will be in a high concentration (high no// of moles) fa to reduce the calculation no//s we do dilution before titration

Question 10

How to get C0 from a diluted solution?

Answer 10

If we’re doing titration to a diluted solution : we should remember to multiply it by the ♉️ in order to get C0

Question 11

Does Addition of distilled water in the beaker change the n of the analyte?

Answer 11

Addition of distilled water in the beaker will not change the n of the analyte => no effect on v eq
Why ? Because the c of analyte decrease (ka2en 3melna dilution)
And the v of the analyte increases (la2en zedna d.w)
HOWEVER the n of the analyte remains constant and n titrant remains constant (acc to Stoichiometry) w kamen V eq will remain cst

Question 12

If the analyte was added more than it should what happens to the n of the analyte?

Answer 12

Changing the volume of the analyte in the beaker changes the n of the analyte => affects Veq
Why? ntitrant/coeff= nanalyte/coef
So nanalyte ⬆️ and n titrant⬆️
So c1×veq/coef= nanalyte ⬆️/coeff
So veq⬆️

Question 13

Note about %by mass after getting the c from titration we can use the c to get % by mass

Answer 13

%by mass =mass of solute/ mass of solution
%by mass= C×Msolute
—————- ×100
dsolution

Question 14

Purpose of starch

Answer 14

Starch is an indicator that gives a dark blue color with iodine (I²) and becomes colorless when iodine is totally consumed

Question 15

Purpose of titration

Answer 15

Volumetric titration consists of the addition of a determined volume of a titrating solution with known concentration C1, to an exact volume of a solution of unknown concentration C₂ to be
determined.
⇒ It is based on a rxn which occurs between the titrating solution (titrant) and the solution to be titrated (analyte)

Question 16

Rule of titration

Answer 16

ntitrant
—————– added from the buret
coeff to reach equivalence
= n analyte
—————- initially present in the
Coeff beaker
→c1×veq c2 ×v2
———- = ———-
Coeff coeff

Question 17

What is VE

Answer 17

Volume of the titrant needed to be added to reach equivalence

Question 18

In calculation→ the analyte is the one:

Answer 18

Initially present in the beaker

Question 19

In calculation → the titrant is the one:

Answer 19

Added from the buret to reach equivalence

Question 20

When they ask about the dilution factor we also state the rule:

Answer 20

upon dilution number of moles of solute
is conserved:
n(-‐)0=n(–)1