Types of chemical reactions
Chemical reactions are processes by which atoms or molecules are redistributed, resulting in different substances with unique properties. Chemical reactions are classified into different categories according to the mechanics of the reactions. The original elements or compounds involved in a chemical reaction are called reactants, and the chemicals that result are called products. Classification of types is presented in Table 2.
Table 2. Types of chemical reactions
Synthesis (combination, construction, composition) reactions
X + Y = Z, where
X, Y are elements or compounds;
Z - new compound
2 H 2 + O 2 = 2H 2O;
H 2O + SO 3 = H 2SO 4;
K 2O + CO 2 = K 2CO 3
Decomposition (desythesis, decomposition, deconstruction) reactions
XZ = X + Z
2 KClO 3 3 O 2↑ + 2 KCl ;
6NaHCO 3 3 Na 2CO 3 + 3 CO 2↑ + 3H 2O;
2 AgI 2 Ag + I 2
Single replacement (single displacement, single substitution, activity replacement) reactions
A + BX = B + AX
2 Mg + TiCl 4 Ti + 2 MgCl 2;
2 Al + 6 CaO Ca 3(AlO 3) 2 + 3 Ca;
Double replacement (double displacement or metathesis) reactions
AB + CD = AD + CB
AgNO 3 + KCl = AgCl↓ + KNO 3;
TiCl 4 + H 2O = 4 HCl↑ + TiO 2↓;
HCl + NaOH = NaCl + H 2O
Oxidation-reduction reactions (Red-Ox)
A z + n → A (z - n)
B y - m → B (y+m)
2Na + S → Na 2S;
2 KMnO 4 K 2MnO 4 + MnO 2 + O 2
Acid-Base reactions (neutralization)
H + + OH - → H 2O (in net ionic form)
H 2SO 4 + 2 NaOH = Na 2SO 4 + 2H 2O
1. To determine relative molecular mass and molar mass of Potassium Orthophosphate Ê
2. How many atoms and moles of atoms are contained in 64 g of Oxygen
16Î? To calculate a mass of one atom of Oxygen in grams.
3. How many moles of H
2SO 4 are contained in 4,9 grams of this substance?
4. How many moles of Sulfuric acid is it possible to prepare from 6,4 kg of Sulfur?
5. How many moles of slack lime Ñà(ÎÍ)
2 is it possible to prepare from 0,1 g of chalk ÑàÑÎ 3 if chalk completely changed into slack lime?
6. To calculate mass (in g) of molecules of Chlorine Cl
2, Carbonic gas CO 2, ammonia gas NH 3.
7. How many grams of Barium Sulfate BaSO
4 may be prepared from 6,1 g of salt BaCl 2×2H 2O? To calculate the mass of Sulfuric acid used in this reaction.
8. Solution, contained 12,6 g of Nitric acid HNO
3, was mixed with 7,2 g of Caustic soda NaOH. What substance will be rest in surplus and in which quantity?
CHAPTER # 2. ATOMIC STRUCTURE
1. Introduction in General, Organic and Biochemistry, 7
th Edition, by Morris Hein, Leo R. Best, Scott Pattison and Susan Arena, Brooks/Cole Publishing Co., 2001. (Chapters 3, 4, pp. 70-125);
1. General notions
Atom is an electroneutral particle consisted of positive charged nucleus and negative charged electrons. Nucleus is a positive charged component of atom concentrated practically all its mass. Components of nucleus are s (
ð) and s ( n). Sum of protons and neutrons is equal to relative atomic mass ( A: r)
A r = p ++n 0
Nucleus charge of atom is equal to number of element in Periodical Table (Z):
Example: To consider structure of atom
Na) = 11
Positive charge of atomic nucleus – 11
Number of electrons - 11
In nucleus: p +- 11
0- 12 ( A r - p + )
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