Title Chemistry Ultra HD Maps.pdf ✅

m Matter can exist in three physical states viz solid, liquid and gas MATTER ELEMENTS COMPOUNDS MIXTURES HETEROGENOUS MIXTURES HOMOGENOUS MIXTURES PURE SUBSTANCES m A mixture contains particles of two or more pure substances in any ratio. m Movement of air follow pressure gradient. m In Homogeneous mixture, components completely mix with each other. m In Heterogeneous mixture, composition is not uniform. m Constituent particles of pure substance have fixed composition. m Compound is formed when two ore more atoms of different elements combine together in definite ratio. m Properties are of two types viz. physical and chemical properties. m Physical properties can be measured or observed without changing the identity or the composition of the substance. m Chemical properties requires a chemical change to occur. m Colour, odour, melting point, density etc are some physical properties. m Composition, combustibility, reactivity with acids and bases are examples of chemical properties. m Quantitative measurement of physical properties represented by a number followed by units. m SI system has seven base units. m Base physical quantities and their units. Length (m) Mass (kg) Time (s) Electric current (A) Thermodynamic Amount of substance (mol) Temperature (K) Luminous intensity (cd) SOME PREFIX USED IN SI SYSTEMS ARE –12 –9 –6 –3 –2 10 (pico), 10 (nano), 10 (micro) 10 (milli), 10 (centi), 3 6 9 10 (kilo), 10 (mega) 10 (giga) SOME COMMON UNITS m 3 3 1 L = 1000 mL = 1000 cm = 1 dm , °F = 9/5 (°C) + 32, K = °C + 273.15 m Scientific notation is exponential notation in which any number n represented in N × 10 , where n is exponent having positive or negative values and N is number between 1.000 ... and 9.999 ..... m Significant figures are meaningful digits which are known with certainity plus one which is estimated or uncertain. m Rules for determining the number of significant figures. m All non zero digits are significant. m Zeros preceding to first non-zero digit are non significant. m Zeroes between two non-zero digits are significant. m Zeroes at the end or right of a number are significant provided they are on the right side of decimal point. m Counting numbers have infinite significant figures. m In a number written in scientific notation, all digits are significant. m Precision refers to the closeness of various measurements for the same quantity. m Accuracy is the agreement of a particular value to the true value of the result. m In addition and subtraction of significant figures the result cannot have more digits to the right of the decimal point than either of the original numbers. m In multiplication and division of significant figures the result must be reported with no more significant figures as are there in the measurement with the fewer significant figures. 1 CLASSIFICATION OF MATTER 3 UNCERTAINTY IN MEASUREMENT 2 PROPERTIES OF MATTER AND THEIR MEASUREMENT m Chapter 1 Some Basic Concepts of Chemistry -
m One atomic mass unit (amu) is defined as a mass exactly equal to one-twelfth of the mass of one –24 C-12 atom, 1 amu = 1.66056 × 10 g. m At present amu has been replaced by unified mass (u) m Average atomic mass can be computed when we take into account the existence of isotopes and their relative abundance. m Molecular mass is the sum of atomic masses of the elements present in a molecule. m Formula mass is used instead of molecular mass for ionic solids as in solid state they do not exist as a single entity. m Empirical formula represents the simplest whole number ratio of various atoms present in a compound, whereas, the molecular formula shows exact number of different types of atoms present in a molecule of a compound. m Important points for rounding off the numbers. If the rightmost digit to be removed is more than 5, the preceding number is increased by one. l l If the rightmost digit is less than 5, the preceding number is not changed. l If the rightmost digit is 5 then preceding number increased by 1 only if it is an odd number. m Method used to interconversion of unit is known as dimensional analysis, unit factor method. m Law of conservation of mass conclude that in all physical and chemical changes, there is no net change in mass during the change. m Law of definite proportions/composition stated that a given compound always contains exactly the same proportion of elements by weight. m Law of multiple proportions stated that, if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of other element are in the ratio of small whole number. m Gay Lussac's law of gaseous volume : When gases combine or are produced in a chemical reaction they do so in a simple ratio by volume, provided all gases are at same temperature and pressure. m Avogadro's law proposed that equal volumes of all gases at same temperature and pressure should contain equal number of molecules. m Dalton's Atomic Theory proposed to following points l Matter consists of indivisible atoms. l All atoms of a given element have indentical properties, including identical mass, atoms of different elements differ in mass l Compounds are formed when atoms of different elements combine in a fixed ratio Chemical reactions involve l reorganisation of atoms. These are neither created nor destroyed in a chemical reaction. 4 LAWS OF CHEMICAL COMBINATION m Stoichiometry deals with calculation of masses (sometime volume) of the reactants and products involved in a chemical reaction. m Reactant, which gets consumed first, limits the amount of product formed is called limiting reagent. m A majority of reactions are carried out in solutions. The concentration of a solution can be expressed in following ways. m Mass percent = Mass of solute × 100 / (Mass of solution) m Mole fraction of solute = No. of moles of solute/No. of moles of solution m Molarity (M) = No. of moles of solute / Volume of solution in litres For dilution of solutions, M V = M V l 1 1 2 2 m Molality (m) = No. of moles of solute/Mass of solvent in kg. 7 STOICHIOMETRY AND STOICHIOMETRIC CALCULATIONS 5 ATOMIC AND MOLECULAR MASS m Mole (Symbol, mol) is seventh base quantity for amount of a substance. m 23 One mole contains exactly 6.02214076 × 10 elementary entities. This number is the fixed numerical value of the Avogadro's constant (N ). A m The mass of one mole of a substance in grams is called its molar mass. m Mass% of an element = Mass of that element in the compound × 100 / Molar mass of the compound. 6 MOLE CONCEPT AND MOLAR MASSES 2 Some Basic Concepts of Chemistry NCERT Maps -
NCERT Maps Some Basic Concepts of Chemistry 3 1. Incorrect boiling point of water is [NCERT Pg. 10] (1) 373 K (2) 100°C (3) 212°F (4) 98.6°F 2. Number of significant digits in 0.200 g is [NCERT Pg. 12] (1) 1 (2) 2 (3) 3 (4) 4 3. Law of multiple proportions is not valid for the pair of [NCERT Pg. 15] (1) H2O and H2O2 (2) CO and CO2 (3) CH4 and CO2 (4) CH4 and C2H6 4. Select the incorrect statement regarding Dalton’s atomic theory [NCERT Pg. 16] (1) Matter consists of indivisible atoms (2) Atoms of given element have identical properties (3) Compounds are formed when atoms of different elements combined in a fixed ratio (4) Atoms are created or destroyed in a chemical reactions 5. An element has two isotopes having atomic mass 10 and 15 u respectively. If the % abundance of lighter isotope is 80% then the average atomic mass of the element is [NCERT Pg. 17] (1) 9 u (2) 11 u (3) 12 u (4) 14 u 6. Formula mass is used instead of molecular mass in the case of [NCERT Pg. 17] (1) H2O (2) NaCl (3) He (4) H2 7. 88 g of CO2 contains (NA = Avogadro’s No.) [NCERT Pg. 18] (1) NA molecules (2) 2NA molecules (3) 0.5 NA molecules (4) 4NA molecules 8. In which molecule, mass % of both elements in the molecule are equal? [NCERT Pg. 19] (1) CO (2) SO2 (3) NH3 (4) H2O2 9. A hydrocarbon contains 80% carbon by mass. The empirical formula of the hydrocarbon is [NCERT Pg. 19] (1) CH (2) CH2 (3) CH3 (4) CH4 10. Mole(s) of CO2 gas obtained at STP, when 32g CH4 reacted with 32 g of oxygen is [NCERT Pg. 20] (1) 0.5 (2) 1 (3) 2 (4) 3 11. Mass of one CO molecule in gram is [NCERT Pg. 18] (1) 4.65 × 10–23 (2) 1.66 × 10–24 (3) 3 × 10–24 (4) 6.22 × 10–23 12. If 2 mol of N2 and 3 mol of H2 mixed together to produce NH3 then select the correct option. [NCERT Pg. 22] (1) N2 is limiting reagent (2) 1 mole of NH3 will be formed (3) H2 is limiting reagent (4) N2 and H2 both are limiting reagents 13. The aqueous solution contains 2g of solute in 18 g solution. The mass% of solute is [NCERT Pg. 23] (1) 11.1% (2) 10% (3) 12.5% (4) 80% 14. A gaseous mixture of CH4 and O2 contains equal masses of both. The mole fraction of CH4 in the mixture is [NCERT Pg. 23] (1) 1 2 (2) 1 3 (3) 2 3 (4) 1 4 15. In order to prepare 500 mL, 0.2 M NaOH solution, the mole(s) of NaOH required is [NCERT Pg. 23] (1) 0.1 (2) 0.2 (3) 1 (4) 2 -