81 10.01x+11.01-11.01x=10.81 -1.00x=0.2 X=0.2 The Mole and Avogadro’s constant Mole: the SI unit that is used to measure how much of a substance. (balanced eqn coefficient are moles) Converting Moles -> number of particles Number of Moles = number of particles / Avogadro’s constant Avogadro’s constant: 6.02214179 x 10^23 Converting Moles to Mass/molar mass Molar Mass: how much grams per mol of an element = atomic mass Number of Moles = mass / Molar Mass Percentage Composition Laws of
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Synthesis Procedure 1 -1.0 Introduction A Cobalt-Amine-Halide compound is synthesized from cobalt (II) chloride hexahydrate. An orange-tinted solid is produced and is considered to be unknown since the specific ligand amounts are unknown. By determining the percent composition of various elements and compounds in the unknown‚ its true identity can be predicted. Chloride‚ ammonia‚ and cobalt are three examples of percent compositions determined to help narrow the selection of possible unknowns
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60108 x 68.92558amu .39892 x 70.9247005 average atomic mass = 69.723amu The Mole (Section 3.2) In chemistry‚ we use the counting unit of a mole (mol). This is defined as the amount of particles that are in exactly 12.00 g of the isotope 12C. This number is 6.022 x 1023. Using this same relationship‚ it can be reasoned that 6.022 x 10 23 amu = 1.000 g. Therefore‚ the average mass of one mole of any element in grams is equal to the average atomic weight‚ also called the average
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Eggshell Lab Lab Set-Up: Materials: * pipette with pipette bulb * conical flask * 1 beaker * 1 molar sodium hydroxide solution * 2 molar hydrochloric acid solution * 1 funnel * 1 piece circular filter paper * crushed poultry eggshell * crushed farm eggshell * phenolphthalein * Distilled water * White tile * Paper tray * burette in burette stand * electronic scale Procedure: Step 1: Standardization of the NaOH solution using
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calcium in water (b) Adding silver nitrate solution to sodium chloride solution A36.2 (p.36-7) (a) Rate of formation of NO2(g) == 0.24 mol dm–3 s–1 (b) From the equation‚ mole ratio of NO2 to N2 = 2 : 1. Rate of consumption of N2(g) =× Rate of formation of NO2(g) =× 0.24 mol dm–3 s–1 = 0.12 mol dm–3 s–1 (c) From the equation‚ mole ratio of NO2 to O2 = 2 : 2 = 1 : 1. Rate of consumption of O2(g) = Rate of formation of NO2(g) = 0.24 mol dm–3 s–1 A36.3 (p.36-12) (a) Instantaneous rate of reaction
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(a) simplete ratio of atoms of each element in a compound (1) 1 (b) (1) × 12 (1) (or definition in terms of moles) 2 (c) CHO = 29 = 6 (1) C6 H6 O6 (1) 2 (d) CH4O+ O2 CO2+2H2O (1) 1 [6] 3. (a) (i) (1) = 1.64(1) allow 1.63 to 1.64 PV = nRT (1) V = (1) if no × 3 CE allow use of p = 100 if answer in dm3 (1) allow 0.162 to 0.166 allow conseq on moles CH2NO2 5 (ii) V = V1 × (1) allow conseq on vol of gas products in (i) = 0.410 (m3) (1) allow 0.4 to
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followed: Mg + 2HCL H2 + Mg2+(aq) + 2Cl-(aq) In this experiment there is a one to one relationship between the number of moles of hydrogen gas evolved and the moles of magnesium metal consumed in the reaction. Therefore in the finding of the experiment moles of H2 evolved is equal to the moles of Mg consumed‚ and atomic weight of Mg is equal to the weight of Mg consumed per moles of H2 evolved. Procedure 1st. Obtain a 600ml beaker‚ add 300ml of water 2nd. add 30ml of HCl (2M) to the beaker
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penalise for missing units 3 b) Moles of solution A 8.5 x 0.25 ½ = 0.002125 ½ moles 1000 c)i) Moles of HCl in 25cm3 of solution D: HCl + NaOH NaCl + H2O 1 : 1 ½ Moles of HCl in 25cm3 = 0.002125 ½ ( Mole ratio) ii) Moles of HCl on 100cm3 of solution D 25 0.002125 100x 0.002125 ½ = 0.0085 moles ½ 25 iii) Moles of HCl in 100cm3 Solution B: 0.5 moles 1000cm3 0.5 x 100cm3 = 0.05moles
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Objective: To determine relative molecular mass of a soluble base‚ X2 CO3 by carrying out an acid-base titration with the following reaction ‚ knowing the amount of hydrochloric acid used and the amount of substance Z used. Hypothesis: The X in substance Z is a group 1 element because substance Z is a soluble metal carbonate and would most likely be sodium or potassium because these elements are commonly used. Materials 100 cm3 beaker‚ 250 cm3 beaker‚ 250 cm3 volumetric flask with stopper
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and the average change in mass of burner for each of the fuels. The averages were based on five trials. PropanolTheoretical Heat of Reaction: Bonds Broken Bonds Formed Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole) Type of Bond Bond Energy (KJ/mole) Number of Bonds Total (KJ/mole) C-H 412 7 2884 C=O 802 6 4812 C-C 348 2 696 H-O 463 8 3704 O=O 496 5 2480 C-O 366 1 366 O-H 463 1 463 Total 6889 Total 8516 Table 5: Shows the theoretical heat change in enthalpy for Propanol From
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