Using English to Calculate
Stoichiometry
STOICHIOMETRY is a branch of chemistry that studies the
quantitative relationship of the composition of chemicals and their reactions.
A. BASIC LAWS OF CHEMICALS
- LAW MASS LAW = LAVOISIER LA
"The mass of substances before and after the reaction is fixed".
Example:
Hydrogen + oxygen of hydrogen oxide
(4g) (32g) (36g) - PERSONAL COMPARATIVE LAW = PROUST LEGAL
"The ratio of the mass of the elements in each compound is fixed"
Example:
A. In the compound NH3: mass N: mass H
= 1 Ar. N: 3 Ar. H
= 1 (14): 3 (1) = 14: 3 - LEGAL COMPARATIVE LAW = LEGAL DALTON
"If two elements can form two or more compounds for the mass of one element equal to the number then the ratio of the mass of the second element will be proportional to the integer and the simple".
Example:
When the Nitrogen element of the oxygen dispensed can be formed,
NO where the mass N: 0 = 14: 16 = 7: 8
NO2 where the mass N: 0 = 14: 32 = 7: 16 - BOYLE LAW
This law is derived from the ideal gas state equations with
N1 = n2 and T1 = T2; So obtained: P1 V1 = P2 V2 - GAY-LUSSAC LAW
"The volume of gases reacting with the volume of the gases of the bile reaction measured at the same temperature and pressure will be proportional to simple den
So for: P1 = P2 and T1 = T2 apply: V1 / V2 = n1 / n2 - AVOGADRO LAW
"At the same temperature and pressure, the same volumes of gases contain the same number of moles. From this statement it is determined that in the STP state (0 ° C 1 atm) 1 mole per volume of 22.4 liters volumes this volume is referred to as the molar volume of gas
B. MASS ATOM AND MASS FORUM
- Relative
Atomic Mass (Ar)
Is the ratio between the mass of 1 atom with 1/12 mass 1 carbon atom 12 - Relative
Molecular Mass (Mr)Is a comparison between the mass of 1 molecule of the compound with 1/12 mass 1 carbon atom 12. The relative molecular mass (Mr) of a compound is the sum of the atomic mass of its constituent elements.
C. CONCEPT
MOL
1 mole is a unit of chemical number whose number of atoms or
molecules is equal to the Avogadro number and its mass = Mr compound.. If the number is Avogadro = L then
L = 6.023 x 1023
1 mol atom = L of atomic fruit, its mass = Ar of the atom.
1 mol molecule = L molecular fruit mass = Mr molecule
please give me one problem example about stoichiometry
BalasHapusWhat is the volume of 8.5 grams of ammonia (NH3) at 27 ° C and 1 atm pressure?
Hapusanswer :
5 g amoniak = 17 mol = 0.5 mol
Volume amoniak (STP) = 0.5 x 22.4 = 11.2 liter
Boyle-Gay Lussac Law:
P1 . V1 / T1 = P2 . V2 / T2
1 x 112.1 / 273 = 1 x V2 / (273 + 27) V2 = 12.31 liter
how do you know when an equation is unbalanced?
BalasHapusWhen there are an unequal number of atoms between the two side. For example, having 5 Oxygen on one side and 2 on the other would be imbalanced
HapusGive an example of determining the Relative molecular mass ?
BalasHapusWhat is the relative molecular mass of NH3?
Hapusanswer :
We know Ar of: H = 1 ; N = 14, so we can sum all the Ar and we can get Mr of NH3 is 17
If the reactions have different koefision, can it influence the lavoiser law?
BalasHapusNo, it doesn't, because in the lavoiser law not talking about koefision but in the lavoiser law talking about the mass.
HapusGive examples of problems relating to Law Gay Lussac law.
BalasHapusDetermine the amount of volume of hydrogen gas burning with 16 liters of oxygen gas and air vapor.
Hapusanswer : To determine the volume ratio we have to find the ratio of the gas coefficient in the reactivity.
H2 (g) + O2 (g) → H2O (g) (we agree on the reaction)
2 H2 + O2 → 2 H2O (equivalent)
From the above reaction, the comparison of coefficient 2 (hydrogen): 1 (oxygen): 2 (water vapor)
If we have 16 liters of oxygen gas, then the required hydrogen volume
2/1 x 16 = 32 liters of hydrogen gas
give me an example problem of avogadro law
BalasHapusAt certain temperatures and pressures, N2 gas is reacted with H2 gas to NH3 gas. If H2 gas reacts as much as 7.5 × 1023 molecules, what is the number of NH3 molecules that are formed?
HapusCalculate the number of molecules in 2 moles of Calcium Chloride
BalasHapus1 moles equals to 6,022 x 10 to 23, so if 2 moles equals to 2 x 6,022 x 10 to 23 its equals to 12,022 x 10 to 23
HapusGive another example of dalton law
BalasHapusSulfur (S) and oxygen (O) form two types. The sulfur content in compound I is 50% and II 40%. Does Dalton's law apply to that?
HapusThere are differences in the ratio that uses the volume, pressure, mole, coefficient, meaning if one of them, whether one of them can replace one of the other?
BalasHapus