EXPERIMENT REPORTMASS OF SUBSTANCES IN CHEMICAL REACTION

GROUP V :

PUTRI MEGA ANANDA (123 194 205 )

ZAIMATUL UMAH (123 194 232)

RADIAN DANY APRILIA (123 194 236)

THE STATE UNIVERSITY OF SURABAYAFACULTY OF MATHEMATICS AND NATURAL SCIENCES

DEPARTMENT OF CHEMISTRY 2012

A. TITTLE : MASS OF SUBSTANCES IN CHEMICAL

REACTION

B. DATE OF EXPERIMENT : October, 16th 2012

C. PURPOSE : Learning about Law of Mass Conservation

D. THEORY :

The law of conservation of mass, also known as the Lomonosov-Lavoisier

law. Lomonosov-Lavoisier law is a law that states the mass of a closed system is

constant despite the wide range of processes in the system (in a closed system mass of

substances before and after the reaction is the same (fixed / constant)) . Statements

that are commonly used to express the law of conservation of mass is the mass can

change form but can not be created or destroyed. For a chemical process in a closed

system, the mass of the reactants must equal the mass of the product.

The law of conservation of mass is widely used in fields such as chemistry, chemical

engineering, mechanics, and fluid dynamics. Based on the science of special

relativity, conservation of mass is a statement of conservation of energy. The mass of

the particles that remain in a system equivalent to the energy momentum of its center.

In some instances the radiation, it is said that the apparent mass change into energy.

This occurs when an object is transformed into kinetic energy / potential energy and

vice versa. Since mass and energy related, in a system that gets / expend energy, the

mass in very small amounts will be created / missing from the system. However, in

almost all events that involve changes in energy, law of conservation of mass can be

used as mass changed very little.

Example of the law of conservation of mass

The law of conservation of mass can be seen in the reaction to the formation of

hydrogen and oxygen from water. When hydrogen and oxygen formed from 36 g of

water, then when the reaction takes place until all the water runs out, the masses will

be obtained product mixture of hydrogen and oxygen is 36 g. When the reaction still

leaves the water, the mass of a mixture of hydrogen, oxygen and water unreacted

fixed at 36 g.

History of Law of Conservation of Mass

Law of conservation of mass, formulated by Antoine Lavoisier in 1789. Because of

this result, it is often referred to as the father of modern chemistry. Earlier, Mikhail

Lomonosov (1748) also has proposed a similar idea and has been proven in

experiments. Previously, the conservation of mass, difficult to understand due to the

force of Earth's atmosphere buoyan. Once the style is understandable, the law of

conservation of mass to be of key importance in changing alchemy into modern

chemistry. When scientists understand that the compound has never lost when

measured, they began to study the quantitative transformation of compounds. This

study led to the idea that all the chemical processes and transformations take place in

a fixed amount of mass of each element.

The law of conservation states that a particular measurable property of an isolated

physical system does not change as the system changes. Here is a list of some of the

laws of conservation that never show inappropriate. (Actually, in general relativity,

energy, momentum, and angular momentum is not conserved because no general

curve time space "manifold" which does not have a murder to translational symmetry

or rotation).

Chemicals associated with the interaction of matter that could involve two substances

or between matter and energy, especially in relation to the first law of

thermodynamics. Traditional chemistry involves interactions between chemicals in a

chemical reaction, a change of one or more substances into one or more other

substances. Sometimes the reaction is driven by enthalpy considerations, such as

when two substances such high enthalpy elemental hydrogen and oxygen react to

form water, a substance with a lower enthalpy. Chemical reactions can be facilitated

with a catalyst, which is generally an other chemicals involved in the reaction media

but not consumed (eg : sulfuric acid which catalyzes the electrolysis of water) or

immaterial phenomena (such as electromagnetic radiation in photochemical

reactions). Also deal with traditional chemical analysis of chemical substances, both

inside and outside of a reaction, as in spectroscopy.

D. DESIGN OF EXPERIMENT

1. PICTURE SERIES OF EXPERIMENT

2. EQUIPMENT AND MATERIALS :

Equipment :

Erlenmeyer = 1 piece

Rubber cork = 1 piece

Small test tube = 1 piece

Yarn = ± 40cm

Balance = 1piece

Materials :

CuSO4 0,2 M = 5 ml

NaOH 0,2 M = 10 ml

Pb(NO3)2 0,2 M = 5 ml

KI 0,2 M = 10 ml

3. Experiment Steps

1. Pouring 10 ml of NaOH 0,2 M into Erlenmeyer, beside that pouring 5ml of

CuSO4 0,2 M into small test tube. Putting filled small test tube into the

Erlenmeyer (test tube hanged by yarn) then covered it with cork.

2. Balancing Erlenmeyer and its fill, then writing down the mass.

3. Canting small test tube so that both of substances are mixed. Observing what happened after that.

4. Balancing Erlenmeyer and its fill, then writing down the mass (after reaction).

5. Pouring 10 ml of KI 0,2 M into Erlenmeyer, beside that pouring 5ml of

Pb(NO3)2 0,2 M into small test tube. Putting filled small test tube into the

Erlenmeyer (test tube hanged by yarn) then covered it with cork.

6. Balancing Erlenmeyer and its fill, then writing down the mass.

7. Canting small test tube so that both of substances are mixed. Observing what happened after that.

8. Balancing Erlenmeyer and its fill, then writing down the mass (after reaction).

E. PROCEDURE

Entered to Reaction tube

Entered to Erlenmeyer tube Bonded with yarn entered to Erlenmeyer and closed the

mouth with rubber cork

Measure with ohausee balance

Write the mass

Sloping the reaction tube, so both of the solution can mix

Measure again with ohausee balance

Mass Before Reaction same after Reaction

Erlenmeyer Flask

Mass Before Reaction

Reaction Tube

Erlenmeyer Flask

10 ml NaOH 0.2 M

Reaction Tube

5 ml CuSO4 0.2 M

Mass Before Reaction same after Reaction

Erlenmeyer Flask

Mass Before Reaction

Reaction Tube

Erlenmeyer Flask

10 ml KI 0.2 M

Reaction Tube

5 ml Pb(NO3)2 0.2 M

F. RESULT OF EXPERIMENT

No Prosedure Result Reaction Conclution

1

1.2.3.

- The mass of

substance before

and after the

reaction are same.

- Mass before

reaction is 154.4

grams and mass

after reaction is

154.4 grams.

- In the reaction

produce sedimen,

and the colour is

young blue.

-The changed of

color are occur.

-The colour of

sedimen : dark blue.

- The color of

NaOH : no colour,

CuSO4 : : young

blue

- 2NaOHaq) +

Cuso4(aq)

(reactan)

- 2NaOHaq) +Cuso4(aq)

➝Na2SO4(aq)+

Cu(OH)2 (s)

-Mass can

change if

rubber cork

opened

-Mass nothing

will change

despite

denature of the

exchange

between the

substance of

the system.

- the

conservation

law of mass

proved with

result of mass

before reaction

same with

mass after

reaction.

Mass Before Reaction same after Reaction

Erlenmeyer Flask

Mass Before Reaction

Reaction Tube

Erlenmeyer Flask

10 ml NaOH 0.2 M

Reaction Tube

5 ml CuSO4 0.2 M

Mass Before Reaction same after Reaction

Erlenmeyer Flask

Mass Before Reaction

Reaction Tube

Erlenmeyer Flask

10 ml KI 0.2 M

Reaction Tube

5 ml Pb(NO3)2 0.2 M

Na2SO4(aq)

+ Cu(OH)2 (s)

(reaction)

-2KI(aq)+Pb(NO3)2(aq)

(reactan)

-2KNO3(aq) +PbI2(s)

(product)

-Mass before

reaction is 155,8

grams and mass of

the reaction 155,8

grams

- There is occur

sediment in that

reaction and the

sediment and

reaction color is

yellow.

-There is no color in

KI reaction

-Pb(NO3)2 have not

color.

- the mass of

substance before

and after reaction is

the same.

➝2KNO3(aq) +PbI2(s)

2KI(aq)+Pb(NO3)2(aq)

F. ANALYSIS

To know about the mass of substance in chemical reaction, first we take 5 ml of CuSO4 0,2 M in test tube while take 10 ml of NaOH 0,2 M in Erlenmeyer. Then put test tube in Erlenmeyer (test tube hanged by yarn) then covered Erlenmeyer with cork. And then we balance Erlenmeyer and its fill, then writing down the mass of it. From the balance, we get the data that mass of it before reaction is 154,4grams. After that, we react both of substance. Repeat to balance the mass after reaction and we get the data that mass is the same with before, 154,4 grams. The chemical reaction is

CuSO4(aq)+2NaOH(aq) → Na2SO4(aq) + Cu(OH)2(s)

For second experiment, we do it in the same way with first experiment. But, we change CuSO4 with 5ml of Pb(NO3)2 0,2M and NaOH changed with 10 ml of KI 0,2M. From the experiment we get data that mass before reaction is 155,8 grams. And after reaction the mass is same, 155, 8 grams. The chemical reaction is

2KI(aq)+Pb(NO3)2(s)→ 2KNO3(aq) + PbI2(s)

G. DISCUSSION

To proof the Law of Conservation of Mass we do two experiments. First experiment, we use CuSO4 react with NaOH. And the second experiment we react Pb(NO3)2 with KI. From both of the result we know that there are nothing change with the mass in chemical reaction (mass before reaction and mass after reaction). It is because we covered the Erlenmeyer with cork, so the gasses that maybe produce can not came out. In our experiment there is an accident because we spent lot of time to balancing the balance, so that the color of our second experiment change become dark green with sediment, but the change of color dosn’t make effect to the mass of reactions

H. CONCLUSIONMass can change if rubber cork opened. Mass nothing will change despite

denature of the exchange between the substance of the system. The conservation law

of mass proved with result of mass before reaction same with mass after reaction.

I. ANSWER OF QUESTION

1 Law is a readily observable fact about something. It is something that is obvious and undeniable.

Theory is an advanced hypothesis. An hypothesis is a plausible, testable explanation of how a phenomenon works and why it works that way.

2 Theory Dalton said that the matter consist of atom that can’t divided. Every substance consist of atom with identical characteristic and mass, and the substance formed if the atom of some element and collect in constant composition.

And the law of conversion mass said mass before and after reaction is same.

So it caused atom can’t be divided and has identical characteristic and mass so mass before and after reaction is same.

3 When magnesium was burned, appear the reaction 2Mg + O2 → 2MgO

so, the mass of MgO is bigger than Mg, because there is mass increase of O2 to Mg

4 Experiment 1: CuSO4(aq)+2NaOH(aq) → Na2SO4(aq) + Cu(OH)2(s)

Experiment 2: 2KI(aq)+Pb(NO3)2(s)→ 2KNO3(aq) + PbI2(s)

REFERENCE

en.wikipedia.org/wiki/chemical_reaction, 17 October 2012 at 18:59.

ariphudien.blogspot.com/2011/02/blog-post.html, Selasa, 15 Februari 2011

Tim Kima Dasar;(2010),Kimia Dasar 1, UNESA, Surabaya.

ATTACHMENT

No Explanation Photo

1. First setting of equipment

2. First experiment, materials of AgCO3 and NaOH

3. Placed AgCO3 and NaOH on the tube

5. Result that produce after mixture AgCO3 and NaOH

5. The substance become green with

sediment because to long waiting for

the measurement.

6. Second setting of equipment

7. Second experiment, materials ofKI and Pb(NO3)2

8. Result that produce after mixture KI and Pb(NO3)2