(Chemistry10th ed., R-Chang,2011) First lecture General Chemistry 402101-4 Chapter 1, p10:29 (Chemistry10th ed., R-Chang,2011) Layla Almazroai
The study of matter and the changes it undergoes First lecture What is chemistry? The study of matter and the changes it undergoes Layla Almazroai
Matter mixture Pure substance compound element First lecture Matter mixture Pure substance compound element Separation by physical methods Separation by chemical methods homogeneous heterogeneous Any thing that occupies space and has mass Matter includes things we can see and touch (such as water, earth, and trees), as well as things we cannot (such as air). A combination of two or more substances in which the substances retain their distinct identities Has a definite composition and distinct properties cannot be separated into simpler substances by chemical means composed of two different elements or more chemically united in fixed proportions. The composition is not uniform The composition is the same throughout Layla Almazroai
a homogeneous mixture a heterogeneous mixture Compound Element Dr AishaDawood
NaCl Salt water Iron sugar air helium water First lecture NaCl Salt water Iron sugar air helium water Compound element homogeneous mixture heterogeneous Layla Almazroai
NaCl Salt water Iron sugar air helium water salad First lecture NaCl Salt water Iron sugar air helium water salad Compound homogeneous mixture element Compound homogeneous mixture element Compound heterogeneous mixture Compound element homogeneous mixture heterogeneous Layla Almazroai
First lecture Matter states The difference between the states is the distance between the molecules. The three states of matter can be converted without changing the composition of the substance Layla Almazroai
Physical Chemical Matter properties First lecture Matter properties Chemical Physical color, mass, size, Shape, Solubility Reactivity flammability is a property when the matter undergoes a chemical change or reaction Can be measured and observed without changing the composition or identity of a substances Layla Almazroai
Measurable properties of matter First lecture Measurable properties of matter Extensive Is additive Intensive Isn't additive depends on how much matter is being considered Does not depend on how much matter is being considered Mass volume Density temperature How can these properties be measured ?? Layla Almazroai
International system of units First lecture Measurement SI Units International system of units Symbol Name of unit Base Quantity m meter Length Kg Kilogram Mass s Second Time A Ampere Electrical current K Kelvin Temperature mol Mole Amount of substance cd candela Luminous intensity Layla Almazroai
International system of units First lecture Measurement SI Units International system of units Symbol Name of unit Base Quantity m meter Length Kg Kilogram Mass s Second Time A Ampere Electrical current K Kelvin Temperature mol Mole Amount of substance cd candela Luminous intensity Layla Almazroai
Prefixes Used with SI Units First lecture Prefix Symbol Multiple of Base Unit Giga G 1,000,000,000 or 109 Mega M 1,000,000 or 106 kilo k 1,000 or 103 deci d 0.1 or 10-1 centi c 0.01 or 10-2 milli m 0.001 or 10-3 micro 0.000001 or 10-6 nano n 10-9 pico p 10-12 Femto f 10-15 Layla Almazroai
Mass and weight 1 Kg = 1000 g = 1 ×103 g Newton (N) First lecture Mass and weight What is the difference between mass and weight? Mass: is a measure of amount of matter in an object Weight: is the force that gravity exerts on an object 1 Kg = 1000 g = 1 ×103 g Newton (N) Layla Almazroai
First lecture Volume 1 L = 1 dm3 = (10 cm) (10 cm) (10 cm) = 1000 cm3 1 L = 1000 ml = 1000 cm3 = 1 dm3 1 mL = 1 cm3 Layla Almazroai
Density g/cm3 for solids g/ml for liquids g/L for gases First lecture Density Density is defined as the mass per unit volume. density = mass/volume d = m V S.I. units for density = kg/m3 g/cm3 for solids g/ml for liquids g/L for gases Layla Almazroai
Density S.I. units for density = kg/m3 density = mass/volume m d = V First lecture Density S.I. units for density = kg/m3 density = mass/volume d = m V A piece of platinum metal with a density of 21.5 g/cm3 has a volume of 4.49 cm3. What is its mass? d = m V m = 21.5 g/cm3 x 4.49 cm3 = 96.5 g m = d x V Layla Almazroai
Temperature T(in Kelvin) = T(in Celsius) + 273.15 9 0F = x 0C + 32 5 First lecture Temperature scales Fahrenheit oF Celsius oC Kelvin K 0F = x 0C + 32 9 5 32 0F = 0 0C 212 0F = 100 0C 273 K = 0 0C 373 K = 100 0C T(in Kelvin) = T(in Celsius) + 273.15 Layla Almazroai
Precision and Accuracy: First lecture Student A Student B Student C 1.964 g 1.972 g 2.000 g 1.978 g 1.968 g 2.002 g Average 1.971 g 1.970 g 2.001 g The true mass of object= 2.000 g Precision: degree of reproducibility of a measured number. Accuracy: how close your measurements are to the true value. Layla Almazroai
Scientific Notation The number of atoms in 12 g of carbon: 602,200,000,000,000,000,000,000 6.022 x 1023 The mass of a single carbon atom in grams: 0.0000000000000000000000199 1.99 x 10-23 N x 10n N is a number between 1 and 10 n is a positive or negative integer uqu chemistry website 9/23/2013
Significant Figures: Any digit that is not zero is significant First lecture Any digit that is not zero is significant 1.234 kg 4 significant figures Zeros between nonzero digits are significant 606 m 3 significant figures Zeros to the left of the first nonzero digit are not significant 0.08 L 1 significant figure If a number is greater than 1, then all zeros to the right of the decimal point are significant 2.0 mg 2 significant figures If a number is less than 1, then only the zeros that are at the end and in the middle of the number are significant 0.00420 g 3 significant figures uqu chemistry website 9/23/2013
First lecture How many significant figures are in each of the following measurements? 24 ml 3001 g 0.0320 𝒎 𝟑 6.4 × 𝟏𝟎 𝟒 molecules 560 kg 2 significant figures 4 significant figures 3 significant figures uqu chemistry website 9/23/2013
Significant Figures: 568.762 = 5.68762 × 𝟏𝟎 𝟐 (6 SF) First lecture 568.762 = 5.68762 × 𝟏𝟎 𝟐 (6 SF) N>1 , 2.00 (3 SF) N<1 , 0.02 (1 SF) 0.20 (2 SF) 0.00000772 = 7.72 × 𝟏𝟎 −𝟔 (3 SF) If addition or subtraction: 1- must have same power before addition or subtraction 2- sig. fig. in the answer is as the smaller digits after decimal point 4.31 × 𝟏𝟎 𝟒 + 3.𝟗× 𝟏𝟎 𝟑 ( 0.39 × 𝟏𝟎 𝟒 ) = 4.70 × 𝟏𝟎 𝟒 (3 SF) 7.4 × 𝟏𝟎 𝟑 + (1 decimal digit: this has the smallest digit) 0.10× 𝟏𝟎 𝟑 = 7.50 × 𝟏𝟎 𝟑 (2 SF)
Significant Figures: First lecture If multiplication or division subtraction: 1- add exponent for multiplication or subtract exponent for division 2- write the answer with the smaller sig. fig. ( 8.0 × 𝟏𝟎 𝟒 ) . (5.00× 𝟏𝟎 𝟐 )=𝟒𝟎× 𝟏𝟎 𝟔 or 4 .0× 𝟏𝟎 𝟕 (2 SF) (3 SF) (2 SF) (2 SF) 4.51 x 3.6666 = 16.53636 ≈𝟏6.5 (3 sf) (5 sf) (3 sf) 6.8 ÷ 112.04 = 0.0606926 ≈ 0.061 (2 sf) (5 sf) (2 sf)
First lecture Layla Almazroai [ Length ] L 1.00m 100 cm 1.094 yd 1000 mm .00100 km 1.00x106 microns 1.06x10-16 light yr 3.28 ft 39.4 in 1.00x1010 A 6.21x 10-4 mile .4926 Delzell [ Area ] L2 1.00m2 0.2427 Delzell2 [ Volume ] L3 1.00L 1000 mL 1000 cm3 1.00x 10-3 m3 .264 gal(US liq) 1.06 qt(US liq) 61.0 in3 ** .0353 ft3 [ Mass ] M 1.00kg 1000 g .0685 slug 6.023x1026 AMU .0275 Eisen [ Density ] M/L3 1.00g/mL 1.00kg/L 1.00x103 kg/m3 0.002 Lenker [ Time ] T 1.00h 60.0 min 3600 s .0417 d .00595 week 1.14x10-4 y 1.14x10-6 Cappel [ Velocity ] L/T 1.00m/s 1.00x10 –4 Lucey [ Force ] ML/T2 1.00N (newton) 1.00kg m/s2 1.00x105 dyne 1.00x105 g cm/s2 .2248 lb (pound) 1.12x 10 -4 ton 1.00x10-12 WellingTON 6.45 Fig Newtons* 5.18 fat free Fig Newtons* [ Energy ] ML2/T2 1.00J (joule) 1.00N m 1.00x10 7 erg 1.00x10 7 dyne cm .7376 ft lb .239 cal 9.48x10 -4 BTU .00987 L atm 2.78 x 10 –7 kW H 6.24x10 18 eV 1.00 v coulomb [Momentum] ML/T 1.00kg m/s 103 hoogenBOOMS [Pressure ] M/LT2 1.00atm 760 mm Hg 760 torr 1.013x105 N/m2 1.013x10 5 Pa 14.7 lb/in2 1.0x10 –5 Kilgour 29.9 in Hg [ Power ] ML2/T3 1.00W 1.00J/s .00134 horsepower .00100 kW 1.00x107 erg/s 1.00x10 53 Liptack 5.00x1099 RobPerry [Acceleration ] L/T2 1.00m/s2 1.00x10 -4Lucey/s [ Number ] 1.00mole 6.023x1023 5.02x1022 dozen 1.00x1047 Bliz pt [ Frequency ] 1/T 1.00cycle/sec 1.00 hertz 108 Williams 103 Lippincott 103 Karas [Temperature] K (Kelvin) ° C + 273 .141 Jacobs + 226 .141 Jacobs-Abs [ Angles ] 1.00circle 360 deg 21600 min 6.28 radians 1.30x106 sec Layla Almazroai