HOMEWORK EXAM 3: Chapter 19: The half life of 90Sr is 29 years. What fraction of the atoms in a sample of 90Sr would remain 175 years later? Answer 0.166 0.125 0.062 here 0.015 Which relation is not correct? Answer 11p = 11H = proton 0-1e = 0-1β = electron here +10e = +10β= positron 10n = neutron As a result of beta decay‚ the product nucleus is Answer one atomic number lower than the original element. two atomic number
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SPE 167543 Wellbore Stability Management In Depleted And Low Pressure Reservoirs Fekete Paul O.‚ Dosunmu Adewale‚ Anthony Kuerunwa‚ Ekeinde Evelyn B.‚ Anyanwu Chimaroke‚ and Odagme Baridor S.‚ Dept. of Petroleum and Gas Engineering‚ University of Port Harcourt‚ Nigeria Copyright 2013‚ Society of Petroleum Engineers This paper was prepared for presentation at the Nigeria Annual International Conference and Exhibition held in Lagos‚ Nigeria‚ 30 July–1 August 2013. This paper was selected for presentation
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experiment‚ you will react a known amount of sodium carbonate solution with a known amount of calcium chloride solution. The skeletal (unbalanced) equation for the resulting double replacement reaction is: Na2CO3(aq) + CaCl2(aq) Æ NaCl(aq) + CaCO3(s) Note that three of the chemicals have their states or phases designated as (aq) and one is designated as (s). The (aq) represents the term aqueous which means that the substance is soluble and dissolved in water. The (s) means that the
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Final Exam Review Chapter 2 Study Questions 1. Define the following a) element b) compound c) pure substance 2. Classify each of the following as a pure substance or a mixture. For each pure substance‚ indicate whether it is an element or a compound. Which of the mixtures are solutions a) air b) titanium c) oak d) baking soda e) oxygen f) 7-Up g) wine h) carbon monoxide 3. Label each of the following drawings as element‚ compound‚ or mixture (Assume each type of circle
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CUMULATIVE MOLE WORKSHEET (Chemistry IB) 1. How many molecules are present in 27.0 g of distilled water? A. 2.7 x 1024 B. 1.5 C. 9.0 x 1023 D. 4.5 2. How many moles of carbon dioxide will be formed when 32.0 g of methane‚ CH4‚ burns completely in oxygen? A. 1.0 B. 2.0 C. 4.0 D. 8.0 3. How many oxygen atoms are present in 0.5 mole of pentahydrated copper(II) sulfate‚ CuSO4.5H2O? A. 2.5 B. 4.5 C. 3.0 x 1023 D. 2.7 x 1024 4. What is the total number of atoms in 3.0 molecules of propanone‚ CH3COCH3
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9.5 – Industrial Chemistry (Option): Δ. Construct word and balanced formulae equations of all chemical reactions as they are encountered in this module: The EQUILIBRIUM Constant: For the basic reversible reaction‚ depicted as: aA + bB cC + dD; Uses of SULFURIC ACID: Fertiliser Production: Creating ammonium sulfate: sulfuric acid + ammonia ammonium sulfate H2SO4 (aq) + 2NH3 (aq) (NH4)2SO4 (aq) Dehydrating Agent: Dehydration of ethanol: ethanol ethylene + water C2H5OH (l) C2H4 (g) + H2O (l) Dehydration
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Chemistry 11 Final Examination Review - Answers Part A - True or False. Indicate whether each of the following statements is true or false. Correct the false statements. F 1. The mass of an electron is equal to the mass of a proton. The mass of an electron is less than the mass of a proton. T 2. The mass of a proton is approximately equal to the mass of a neutron. T 3. The atomic number represents the number of protons in a nucleus. T 4. The proton has a mass of approximately
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chloride is an aqueous system. The molecular form of the equation is Na2CO3.H2O + CaCl2.2H2O → CaCO3 + 2NaCl + 3H2O As the two reactant salts and sodium chloride are soluble in water but calcium carbonate is insoluble‚ the ionic equation for the reaction is that we present only the ions that react (after removing the spectator ions)we have the net equation as below CO32- (aq) + Ca2+(aq) CaCO3(s) From the balanced net ionic equation‚ 1 mole of carbonate ion from the 1 mole of Na2CO3.H2O(molar
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processing or conventional productions of finer precipitation calcium carbonate (nano-PCC) in turbo-mixing conditions. In this paper‚ the effect of the stirring rate onto morphology‚ particle sizes and reaction time of the precipitated CaCO3 particles was discussed. CaCO3 nano particles with an average particle size of approximately 15.75 nm were successfully obtained by stirring rotation speed at 900 rpm. The structural analysis was conducted using a Scanning Electron Microscope (SEM) and a Field Emission
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chalk and coral. It is produced either as powdered or precipitated calcium carbonate. Calcium carbonate decomposes to calcium oxide and CO2 on heating. Treatment with dilute mineral acids produces corresponding calcium salts with liberation of CO2: CaCO3 + 2HNO3 Ca(NO3)2 + H2O + CO2(g) In this experiment‚ the mineral acid is added in excess to the calcium carbonate and the excess titrated against standard sodium hydroxide. This kind of titration is termed back titration. In
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