Last seen: Jan 25, 2021
2O —> It represents 2 atoms of oxygen (cannot exist independently). O2 —> It represents one molecule of oxygen (made up of 2 atom) can exist f...
The atomicity of the molecules are: (a) Ca(OH)2 → 05 (b) Mg(HCO3)2 → 11 (c) Cu2O → 03 (d) H2SO4 → 07 (e) Al2(SO4)3 → 17 (f) MgCl2 → 03
The chemical formula are: (a) Aluminium carbonate Formula → (b) Calcium sulphide CaS (c) Zinc carbonate ZnCO3 (d) Cop...
The ratio by number of atoms for a water molecule are: Element H O Ratio by mass 1 8 Atomic mass 1 16 = 1 = Simplest ...
Formula unit mass of NaCl = 23 + 35.5 = 58.5 u Formula unit mass of CaCl2 = 40 + (2 x 35.5) = 40 + 71 = 111 u
Atom 1. An atom has no charge. 2. Number of electrons = number of protons. 3. Atom is reactive. Ion 1. An ion has either positive or negativ...
(i) CO2 represents carbon-dioxide. (ii) CO2 is one molecule of carbon-dioxide. (iii) CO2 is one mole of carbon-dioxide i.e., it contains 6.022 x 1...
Relative atomic mass: It can be defined as the number of times one atom of given element is heavier than 1/12th of the mass of an atom of carbon-12. ...
IUPAC —> International Union of Pure and Applied Chemistry approves name of elements. Symbols are the first one or two letters of the element’...
(i) 6.022 x 1023 number of O2 molecules: Mass of 1 mole of O2 molecule = 6.022 x 1023 molecules = 32 g (ii) 1.5 mole of CO2 molecule: Mass of 1 ...
(i) 0.5 mole of C atom: Number of atoms in 1 mole of C atom = 6.022 x 1023 atoms Number of atoms in 0.5 mole of C atom = 6.022 x 1023 x 0.5 = 3....
Number of moles in (i) Molar mass of H2O = 18 g Given mass of H2O = 50 g ∴ No. of moles on 50 g of H2O = 50/18 = 2.78 moles. (ii) Molar mass o...
The formula unit mass of a substance is a sum of the atomic masses of all atoms in a formula unit of a compound. The constituent particles of formula ...
Chemical formula: Copper nitrate —> Cu(NO3) Calcium sulphate —> CaSO4 Aluminium hydroxide Al(OH)3
A group of atoms carrying a charge is known as a polyatomic ion. E.g., Ammonium – NH4+ Nitrate – NO3–
Valency: The combining capacity of an element is called its valency. Valency of the following elements: Magnesium – 2 Aluminium – 3 Chlorine ...
H2O ratio by mass of combining elements 2 : 16 —>1 : 8 (H : O) CO2 ratio by mass of combining elements 12 : 32 —> 3 : 08 (C : O) NH3 ratio b...
Sodium —> Natrium, Gold —> Aurum Potassium —> Kalium, Mercury —> Hydrargyrum
IUPAC is International Union for Pure and Applied Chemistry. It approves the names of elements.
The unit to measure size of atom, is nanometer, size of hydrogen atom is 10-10m.