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4M HCl: This is because the concentration of HCl is more in 4M HCl than 1M HCl. When the concentration of the reactants increases, the number of reactant molecules also increases. That consequently increases the number of effective collision .....
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It is decomposition reaction. MnO2 i.e. manganese dioxide acts as a positive catalyst i.e it accelerates (the rate of chemical reaction) the decomposition of potassium .....
Gram molecular weight of CaCo3 = Ca × 1 + C × 1 + O × 3 .....
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Information obtained is: 1. Nitrogen and hydrogen are reactants and ammonia gas is a product. 2. 1 molecule of N2 reacts with 3 molecules of H2, giving 2 molecules of NH3. 3. It is a reversible reaction. 4. It is addition .....
The atomic weight of an element expressed in gram is called gram atomic weight of that element. The atomic weight of sodium = number of proton + number of neutron .....
A reaction in which acid and base react to form salt and water is called neutralization reaction. The reaction between hydrochloric acid, the strong acid and a sodium hydroxide strong base is called so because the properties of both the substances .....
Reactants Products 1. These are the elements or compounds taking part in a chemical reaction. 1. These are the elements or compounds formed as a result of chemical reaction. 2. Reactants are written on .....
When potassium chlorate is heated, it produces potassium chloride and .....
Calcium reacts with water to produce calcium hydroxide and hydrogen gas. Ca + 2H2O → Ca(OH)2 + .....
Endothermic Reaction Exothermic Reaction 1. A chemical reaction which proceeds with the absorption of heat energy is called endothermic reaction. 1. A chemical reaction which the evolution of heat energy is called .....
NaCl (aq.) + AgNo3 (aq.) → AgCl (s) + NaNo3 (aq.) The reaction involves the exchange of radical and is known as double displacement .....
The molecular formula of water is H2O. Molecular weight of water ( H2O ) = 1 × 2 + 1 × 16 .....
The type of chemical reaction in which an acid reacts with base to form salt and water, is called neutralization reaction. Examples of such reaction are: H2SO4 + 2KOH → K2SO4 + .....
The differences between positive and negative catalyst are: Positive catalyst Negative catalyst 1. It accelerates the rate of chemical reaction. 1. It retards slows down the rate of chemical reaction. 2. Manganese .....
A chemical equation cannot give the information about the time taken for the completion of the chemical .....
The two examples of reversible chemical reaction; H2 + I2 ⇌ 2HI N2 + 3H2 ⇌ .....
The rate of chemical reaction increases with increase in concentration of .....
A chemical reaction expressed by writing the full names reactants and products is called word equation. For example, Magnesium + Oxygen → Magnesium .....
The example of double displacement reaction is AgNo3 + NaCl .....
The four factors that affect the rate of chemical reaction are : a. Temperature b. Catalyst c. A surface area of the reactants d. A concentration of the .....
The number of atoms or molecules or ions in one mole of any substance is known as Avogadro’s .....
Electric Configuration Name of the elements 1s2, 2s2 2p4 Oxygen 1s2, 2s2 2p6, 3s1 Sodium The molecular formula of the compound forms by the combination of these elements is Na2O. The chemical .....
The given metals are arranged according to their chemical reactivity as follows: Gold > Silver > Copper > Iron > .....
The very active metals are found in group IA and very active non-metals are found in group VIIA in modern periodic table. When the atomic size of atom of very active metals is increased, the reactivity of atom is also increased. But when the atomic .....
The electronic configuration of A and B are: A (Oxygen) - 1s2, 2s22p4 B (Aluminum) - 1s2, 2s22p6, .....
The group IA elements in the modern periodic table are known as alkali metals. When we go down in the group IA, the distance between the nucleus and outermost orbit of atoms increases and attraction force between nucleus and electrons of the .....
On moving from left to right in same period, the metallic character of elements decreases as the electropositive character of element decreases and the electronegative character increases. Therefore the metallic properties gradually change into .....
The tendency of an atom to achieve eight electrons in its outermost orbit for the stability during chemical reaction is called octet .....
The valency of an element depends upon the number of electrons of the outermost orbit of an atom i.e. valence .....
Lanthanides are a group of 15 elements from 57 La to 71 Lu. They are kept separately in the periodic table as they have properties similar to Lanthanum (La) and cannot fit in the provided space in the periodic table. Potassium and Calcium lie in the .....
The position of hydrogen is controversy. It has only one electron in its atom and shows many similar properties of the alkali metals (i.e. group IA) and the halogens (i.e. group VII A). It can lose one electron like the elements of group IA and also .....
• These elements are arranged based on their atomic number. The atomic number of elements increases as we move from left to right. • Na is more active between Li and Na because the size of the atom .....
The equation of chemical reaction expressed in short form by a chemical formula is called formula .....
The element A belongs to third period and IA group. The element B belongs to second period and VIA group. The element C belongs to third period and VIIA group. The element A is metal and B and C are .....
The zero group element is inert because they do not take part in chemical reaction as they are in octet state with 8 electrons in their outermost orbit. They do not lose or gain electrons from their outermost orbit. The zero group elements are .....
Position of hydrogen still controversial because it is resemble with both Group IA and VIIA of periodic .....
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. Fluorine is the most electronegative element having a value of .....
• Fluorine (F) and Chlorine (Cl) are most reactive non metals • Sodium (Na) is most reactive metals • Neon (Ne) and Argon (Ar) are the inert .....
These metals are soluble in water and form metallic hydroxides and evolve hydrogen gas. These hydroxides are called alkalis. Therefore the elements of group IA are called alkali .....
The two reasons for placing hydrogen are as follows: • It can lose one electron like other elements of this group in order to combine with other atoms. • It shows electropositive character like .....
The elements mentioned above belong to group VIIA. The reactivity of element decreases from top to the bottom due to increase in size of the .....
The element which is placed in period 3 and has valency 4 is Silicon .....
The valencies of the transition metal depend on the number of electron present in d – .....
The two alkali earth metals are: Beryllium and .....
It is because the non-metal having smaller atomic size is more active than that which has a bigger atomic size. As non-metals have to gain electrons while making a molecule, the smaller atomic size has more force of nucleus for it. Due to this .....
Potassium is more reactive than sodium because both of them are metals having valency 1, but their atomic size is different. The metal having a big atomic size is more active than that which has small atomic .....
The differences between S block and P block elements are as follows: S-block elements P-block elements 1. The s-block elements include the elements of group IA and group IIA. 1. The P-block elements include the elements of .....
A reaction in which heat is evolved is called exothermic .....
The differences between groups and period are as follows: Groups Periods 1. The vertical columns of the periodic table are called groups 1. The horizontal rows of the periodic table are called periods. 2. The valence .....