Formal Report

FORMAL REPORTEXPERIMENT IN BASIC CHEMISTRY I

I. TITLE : CHEMICAL REACTION ORDERII. PURPOSE :

Determine the level of reaction in the reaction between sodium thiocykate ( Na2S2O3 ) in hydrochloric acid ( HCl)

III. BASIC THEORY :The order of reaction , in chemical , with respect to a certain reactant, is defined as

the power to which its concentration term in t kinetics he rate equation is raised. Speed shows the speed of chemical reactions decreaase the concentration of reactans per unit time or velocity increased concentration of the product per unit time.

Example :A B

Speed :

∆(A) = ∆(B)

=∆t = ∆t

The minus (-) sign indicates that the concentration decreases when the time increases. The realtionship between changes in concentration with time change can be decribed as follows:

∆t

∆(B)

solubility

Time (t)

The average speed at time interval is follows:

∆t = - = -

Because the reaction rate is always proportional to the concentration of reactants, the law matematically raection rates for the following chemical reaction:

aA + bB cC + dD

V= k [A]x[B]y

Where :V = the rate of reactionK = decree of the reaction rate

[A] and [B] = concentration A and Bx and y = the level of response to A and B

Reaction rate constant defined as the rate of raction when the concentration of each species in the only depends on the reaction order. Basic reacction is any reaction that provides the necessary products to elucidate the mechanism of a reaction. While the number of molecules taken part in a basic stage is moleculitas.

Order from a reaction which describes the mathematical form of experimental results can be shown if the reaction mechanism is known. Throughout the reaction order can be defined as the sum of the exponents of each reactant. Thus, the reaction order is the price of exponents for a component in the reaction rate.

Law defernsial speed and integralThe relationship between speed and consentration between the concentration and time

can be expresed by the following equation :For example, for the general reaction :

aA + bB cC + dD

Can be expressed

- = =

Differential rate law so that the raection :

= = k [A]X[B]Y

Differential rate law shows how reaction rates depend on the concentration of reactants. To show how concentration depending on the time can be expressed by the integral equation.

a. Reaction degreeBased on the results of the experiment is the N2O5 decomposition reaction of the

reaction rate as follows :

N2O5 (g) 2NO3 (g) + O2 (g)

It can be stated

- = k [N2O5]

If concentration of N2O5 is expressed by A, then :

- = k [A]

- = K dt

- = k

- In A ] = kt ] - = kt or

= o – kt

Thus, when graphed againts time in A will obtain a straight line with slope = -K and intercept.

Slope = tan α = - k

α

time (t)

b. The reaction rate of twoFor example, simple reaction :

2A BThe reaction rate of two, so that:

- = k [A]2

If the prince of K repleaced K, then :

- = k dt

= k

= k

- = kt or = + kt

So that when graphed Z opponent with T will get a straight line with slope = -K, intercept = 1/Ao

Slope = tan α = - k

α

Time (t)

c. The reaction rate is zeroFor example the reaction A B reaction rate is zero.

- = k [A]

- = k

- = k ↔ - - - = kt or A = Ao - kt

When graphed (A) opponent with t will get a sttraight line with slope = -K and intercept = (Ao)

AoSlope = - k

Time ( t )

v. EQUIPMENT

1. TOOL

NO NAME PICRURE AMOUNT

1

2.

3.

4.

Beaker Glass

Measurement Glass

Stopwatch

Pippete

2

2

1

2

2. MATERIALS

NO NAME AMOUNT1.

2.

3.

Aquades

Solution Na2S2O3 0,15 M

Solution HCl 3 M

33 ml

75 ml

29 ml

V. PROCEDURE

1. Enter Na2S2O3 25 ml of solution into 100 ml of beaker glass.

2. Take 4 ml HCl 3M solution and add to the glass beaker containing the solution to step no. 1. While running the stopwatch, then stop the stopwatch at the time of turbidity. Record the time required in table 1.

3. Repeat the above experiment using solution and aqudes as listed in table 1 and table 2.

4. Make graph showing relation between :

a. against [ Na2S2O3 ]

b. against [Na2S2O3 ]2

c. against [ HCl ]

d. against [ HCl ]2

5. Determine the level of reaction to a solution of Na2S2O3 and reaction rates HCl solution.

VI. OBSERVATION DATA

1. Table 1

Product rection of chemistry rate to Na2S2O3No.

Amount of Na2S2O3 (ml)

Amount of H2O (ml)

Councentracy Na2S2O3

Amount of HCl (ml)

Time to reactions (s)

1. 12,5 - 0.15 4 26,22. 10 2,5 0,15 4 20,83. 7,5 5 0,15 4 44,64. 5 7,5 0,15 4 72,15. 2,5 10 0,15 4 229,9

2. Table 2

Product reaction chemistry rate to HCl

No.

Amount of Na2S2O3 (ml)

Amount of HCl (ml)

Amount of H2O (ml)

Councentracy HCl (ml)

Time to reactions (s)

1. 12,5 5 - 3 30,62. 12,5 3 2 3 27,43. 12,5 1 4 3 42,3

VII. ANALYSIS DATAA. Quantitative Analysis

Na2S2O3 reaction rates

1. Finding Molarity Na2S2O3

V1 × M1 = V2 × M2

M2 = Where ; V1 = Volume Na2S2O3

V2 = Volume Na2S2O3 + Volume H2O M1 = Initial concentration of Na2S2O3 (0,15M)

a.) M2 = = = 0,15M

b.) M2 = = = 0,12M

c.) M2 = = = 0,09M

d.) M2 = = = 0,06M

e.) M2 = = = 0,03M

2. Na2S2O3 reaction rates

= *(HCl) = constant

=

Data 1 and 2

=

= ( )x

= (1,25)x

X = 0,424

Data 1 dan 3

=

= x

= (1,67)x

= 1.041

Data 1 and 4

=

= x

= (2,5)x

X = 1,105 Data 1 dan 5

=

= x

= (5)x

X = 1,349

Data 2 and 3

=

= x

= (1,33)x

X = 1,520

Data 2 dan 4

=

= X

= (2)x

X = 1,324

Data 2 and 5

=

= X

= (4)x

= 1,498

Data 3 and 4

=

= X

= (1,5)x

X= 1,184

Data 3 and 5

=

= x

= (3)x

Data 4 and 5

=

= x

= (2)x

X = = = 1,2611

HCl reaction rates1. Finding Molarity HCl

V1 × M1 = V2 × M2

M2 =

Where ; V1 = Volume HCl V2 = Volume HCl + Volume H2O

M1 = Initial concentration of HCl (3M)

a.) M2 = = = = 3

b.) M2 = = = = 1,8

c.) M2 = = = = 0,6

2. HCl reaction rates

= *(Na2S2O3) = constant

=

Data 1 and 2

=

=

= y = 0,216

Data 1 and 3

=

=

= y = 0,201

Data 2 and 3

=

=

= y = 0,395

Y = = = 0,127

Order total and reaction rate equation

Total order = x + y = 1,2611 + 0,127 = 1,3881

V = k (Na2S2O3)x (HCl)y

V = k (Na2S2O3)1,2611 (HCl)0,127

Plot

a) vs [Na2S2O3]

x y0,15 0,03810,12 0,03470,09 0,02240,06 0,01380,03 0,0043

b) vs [Na2S2O3]2

x y0,02250,01440,00810,00360,0009

0,03810,03470,02240,01380,0043

c) vs [HCl]

d) vs [HCl]2

x y9

3,240,36

0,03260,03640,0236

x y3

1,80,6

0,03260,03640,0236

B. Qualitative Analysis

The purpose of this experiment is determining the reaction order in the reaction between sodium thlocykate (Na2S2O3) in Hydrochloric acid (HCl).

The principle of work in this experiment is; first, enter Na2S2O3 to beaker glass. Then, add the HCl to the beaker glass containing the solution to step number 1. While running the stopwatch and stop at the time of turbidity. And repeat the above experiment using solution and aquades as listed in table. Make some graph showing

relation between and Na2S2O3. At the last, determine the reaction order to a solution of Na2S2O3 and reaction rates HCl solution.

And the reaction between Na2S2O3 and HCl in this experiment carried out two kinds :1. Experiment Na2S2O3 reacting with a different molarity of HCl the molarity same.

This experiment aims to determine the reaction order of Na2S2O3.

2. Experiment HCl reacting with a different molarity of Na2S2O3 the molarity same. This experiment aims to determine thereaction order of HCl.

From the result of calculations experimental data, obtained the order of different reactions in each experiment. So, the reaction order is taken the average and obtained that the reaction order Na2S2O3 = 1,2611 and HCl reaction order = 0,127. So :

V = k (Na2S2O3)1,2611 (HCl)0,127

This is not in accordance with the theory, ie :V = k (Na2S2O3)1 (HCl)2

This is affect by;1. The mistake when observe the process of reaction and determine the final limit

reaction. Not only the certain standard that used to determine the find limit that invalid.

2. The carelesly of practican in doing experiment when using the equipment such as measuring glass and beaker glass, that the number is unread.

3. The mistake when calculating the value result of the experiment.

Chemical reactions that occur in this experiment:Na2S2O3 (aq) + 2 HCl (aq) 2 NaCl (aq) + SO2 (g) + S(g) + H2O (l)

VIII. CONCLUSIONSpeed of reaction is the reactant concetration reduced speed or velocity increased

concentration of the product per unit of time. The reaction order is the rank number of the relationship with the concentration of the reation rate can be determined through experiments. Graph showing the relationship between the concentration of the solution either by time or the reverse reaction is the reaction time straight line.

From the experiment is known that the speed is almost always the same reaction is proportional to the concentration of reactants.

Thus, for reaction:Na2S2O3 (aq) + 2HCl (aq) → 2NaCl (aq) + SO2 (g) + S (s) + H2O (g)

Reaction speed :V = k [Na2S2O3]x[HCl]y

Where; V = reaction speedk = reaction rate constant at a given temperaturex = order of reaction rate Na2S2O3

y = order of reaction rate HClObtained from the experiment :- Order reaction against Na2S2O3 = x = 1,2611- Order reaction against HCl = y = 0,127

So that the reaction rate law for the reaction of Na2S2O3 with HCl ;V = k [Na2S2O3]1[HCl]1

Total reaction order = x + y = 1,2611 + 0,127 = 1,3881