Search

# Chemistry - Assignment Example

Summary
This paper presents several assignments that concern chemistry issues. To be precise, there are answers for different tasks. Thus, it is stated, "Be" has 4 protons and 11-4=7 neutrons, because it’s neutral it has 4 electrons and hydrogen like beryllium ion has 1 electron. …

## Extract of sample"Chemistry"

En=-(13.6eV*z²)/n², because z=4
it can be written as En=-16*13.6eV / n²
ii) the dependence of quatum numbers n upon l is given by the following formula
l=n-1
Σ2(2*l+1)=2* n²
iii) n=2 for beryllium, so l=1 and can not be 3
d) iii) energy emitted by photon:
|Einf- E2|= 0+54.4eV=54.4 eV= 54.4*1.6*10^-19 [J]=8,7*10^-18 [J]
8,7*10^-18 [J]
now we should express photon’s frequency from it’ energy:
E=h*f => f=E/h
f= 8,7*10^-18 [J]/6.63*10^-34 [J*s]=1.31*10^16 [1/s]
1.31*10^16 Hz is ultraviolet spectrum
iv) the energy of the lowest energy photon which can be absorbed by beryllium ion is:
E2-E1=-54.4eV+217.6=163.2 eV
v) it could absorb a photon of a lower energy if its electron was on a higher energetic level
i) E1=-16*13.6eV / 1=-217.6eV
E2=-16*13.6eV / 4= -54.4eV
E3=-16*13.6eV / 9 = -3.067eV
Eoo=-16*13.6eV/inf = 0
Question 3
- because ΔH>0 (=29kJ) reaction is endothermic;
- I2+Cl2 =2ICL (-29kJ)
ΔH=2ΔHICL-ΔHCl2-ΔHI2;
- equilibrium will not change as the number of molecules in the left part of the equation equals to the number of molecules in the right part of the equation: I2+Cl2 =2ICL 1+ 1=2
- because it’s endothermic reaction the increase of temperature will cause the shift of equilibrium to the right (forming of ICl);
- the reaction will pass faster with the following rate lg (k^(T2/T1)) where k is the reaction rate coefficient;
- the presence of catalyst will cause the reaction rate to increase, the equilibrium will cause the shift to the right (forming of ICl) as catalyst mainly reduces activation energy. ...Download file to see next pagesRead More
Cite this document
• APA
• MLA
• CHICAGO
(“Chemistry Assignment Example | Topics and Well Written Essays - 250 words”, n.d.)
Chemistry Assignment Example | Topics and Well Written Essays - 250 words. Retrieved from https://studentshare.org/chemistry/1507476-chemistry-assignment
(Chemistry Assignment Example | Topics and Well Written Essays - 250 Words)
Chemistry Assignment Example | Topics and Well Written Essays - 250 Words. https://studentshare.org/chemistry/1507476-chemistry-assignment.
“Chemistry Assignment Example | Topics and Well Written Essays - 250 Words”, n.d. https://studentshare.org/chemistry/1507476-chemistry-assignment.
Click to create a comment or rate a document
CHECK THESE SAMPLES - THEY ALSO FIT YOUR TOPIC
The questions of Chemistry for Life Sciences
...?Chemistry for Life Sciences Keep your sentences short and simple to understand. Correctly answer all questions please (100 Do not directly copy sentences from Wikipedia as we check with Turnitin software. Answer all questions in Section A and Section B in the spaces provided. Write your answers to the questions in Section B in continuous prose, where appropriate. You will be assessed on your ability to use an appropriate form and style of writing, to organise relevant information clearly and coherently, and to use specialist vocabulary, where appropriate. This paper consists of 6 questions on 6 pages. Section A 1 (a) Balance the equation, given below, for the reaction in which H2Se is formed from Al2Se3 Al2Se3 + 6 H2O >...
6 Pages(1500 words)Assignment
Chemistry assignment
...+0.179 = 0.0.429 mol/L Figure 1 Polar and covalent bonds (Source: Lewis) Works Cited Atkins, Peter, and Julio de Paula. ATKINS Physical Chemistry, eighth ed. Oxford: Oxford University Press, 2006. Gilbert, Thomas, Rein Kriss, and Geoffrey Davies. Chemistry: The Science in Context. New York: W. W. Norton & Company, 2003. Lewis, Rob, and Wynne Evans. Chemistry, third ed. Hampshire: Palgrave Macmillan, 1997. "Visual Elements: Patterns in the Periodic Table." Royal Society of Chemistry. 20 July 2009 .... Calculate the value of K at 25oC for the following reaction: 4NH3(g) + 7O2(g)  4NO2(g) + 6H2O(g) R is 0.08206Latm/Kmol and Kp is 9 x 103. Equilibrium constant K is written in terms of partial pressure equilibrium constant Kp as (Lewis): Kp = 1.9×...
3 Pages(750 words)Assignment
Karyotyping (cellular chemistry)
...Answers to Questions: A 47,XX, +21 2. Down’s syndrome (Trisomy 21) B 47, XXY 2. Klinefelter’s syndrome (XXY) C 47, XY, +13 2. Trisomy 13 syndrome Chromosomes bear the information needed by all biological functions. Each species has its own set of chromosomes that, other than bearing physiologically-important genes, also code for defining morphological and/or physiological characteristics that make the species different from others (Gilbert 9). An organism with missing or additional chromosomes will thus have physical or functional differences as compared to another of the same species which bear the normal set of chromosomes. Chromosomes, despite their seemingly linear appearance, are highly complex mostly because of the necessity...
4 Pages(1000 words)Assignment
Assignment (Chemistry subject)
...= 80%/51yrs = 1.6% per year 42- A 3.80ml sample of mercury has a mass of 51.4 g. What is the density of mercury in g/cm^3? Answer: Formulae of density = mass/ volume 51.4g/3.8cm3 = 13.53g/cm3 NOTE: 1ml = 1 cm3 44- A thief plans to steal a bar of gold from a woman’s purse and replace it with a bag of sand. Assume that the volumes of gold and the sand are 350ml each and that the density of sand is 3.00 g/cm^3 a- Calculate the mass of each object Answer: Formulae mass = volume * density = 350cm3*3.00g/cm3 = 1050g NOTE: 1cm3 = 1ml b- Would the woman notice a difference in the weight of her purse? Answer: yes because mercury has a bigger density...
2 Pages(500 words)Assignment
Inorganic chemistry
...INORGANIC CHEMISTRY Chemistry Assignment 11 February Part A Structure, Stereoisomerism, and Nomenclature Sketches of the transition metal complexes and their stereoisomers a) [Co(NH3)6]3+ NH3 NH3 3+ 3HN Co NH3 3HN NH3 Pentamminechlorocobalt (III). There are no other possible isomers Transition metals: the d group elements. b) [FeCl4]- Cl Cl - Fe Cl Cl c) [Co(NH3)4Cl2]+ Cl NH3 + Cl NH3 + Cl Co NH3 3HN Co NH3 H3N NH3 3HN Cl Cis-tetramminedichlorocobalt (III... edn,...
6 Pages(1500 words)Assignment
Hard water in Chemistry
...Table of Contents (A)Experiment 2 (B) Laboratory sheet 3 (C How to calculate the concentration of calcium hydroxide 3 Describe the preparation of 100mL phosphate buffer at pH 7.4, starting from H3PO4 solution (1M) and KH2PO4 (FW 136 g/mol). 5 What is the pH of a solution resulting from mixing 100 mL 0.5M NaOH with 500 mL 0.3M HCl? 6 SHORT ESSAY ON HARDWATER 7 Introduction 7 Origin 7 Temporary hardness 8 Permanent hardness 8 Traditional water softening 8 Alternative methods 8 Health Concerns and issue 9 Negative aspect 9 Conclusion 9 APPENDIX 10 References 12 (A) Experiment Name: Titration Required items: A beaker A burette Phenolphthalein HCL solution calcium hydroxide solution Procedure 20 ml of a solution... of...
2 Pages(500 words)Assignment
Chemical KInetics Chemistry
...absorbent and with a large surface area. The increased surface area greatly increases the rate of the conversion (Leigh, 2007). The use of the iron catalyst provides an alternative pathway with a lower activation energy for the breaking of the bonds between N2 and ­H2. The N2 and H2 get adsorbed onto the catalyst’s surface, forming an iron-enzyme complex: The adsorbed N2 and H2 is combined at a ratio of 3H:1N and the combined mixture is adsorbed onto the catalyst and then cooled, turning it into liquid ammonia. The H2 for the Haber-Bosch process is obtained by adding steam to methane in the presence of a nickel catalyst at a temperature of 700°C: References Burton, G. (2000) The Effect of Concentration on Rate, in Salters Advanced...
6 Pages(1500 words)Assignment
Chemistry assignment
... Advanced biochemistry ll Response to question The anaerobiosis needs the NAD+ regeneration from NADH so as to allow the continuation of glycolysis. Part a Figure 1 shows the fate of the glucose carbon atoms. C-1 (or C-6) becomes C-3 of a glyceraldeldehyde 3-phosphate and pyruvate subsequently. If the decarboxylation of the pyruvate occurs and ethanol is reduced, C-3 would be the C-2 of ethanol given by CH3-CH2-OH. Figure 1. O14 CO + Part b For all the conversion of all the labeled atoms of carbon to 14CO2 from glucose during the fermentation of ethanol, the original label has to be placed on C-3 or C-4 of the glucose as these are changed to the pyruvate carboxyl group. Response to question 2. The fermentation of ethanol in yeast...
2 Pages(500 words)Assignment
Food chemistry
...Interestification and Partial Hydrogenation Interesterification and partial hydrogenation Fatty acids contain a carbonyl group and one or more double bonds. The chemistry of fatty acids involves either or both of these functional groups. 90% of the chemistry of fatty acids and their esters are concerned with the acid ester group, while the double is only to a minor extent. Interesterification is reactions in which fatty acid compound esterified to a glycerol backbone is reacted with fatty acids, alcohols or esters. When applied to oils and fats, it is a reaction between different triglycerides with rearrangements of the acryl groups within and between different triglycerides. The process does not change fatty acid composition... in oil...
3 Pages(750 words)Assignment
Analytical chemistry
... methods that included CV, SWV and most especially the proposed method DPV. Reference Lourencao, B.C., Baccarin, M., Medeiros, R.A., Rocha-Filho, R.C. & Fatibello-Filho, O. (2013). Differential pulse voltammetric determination of Albendazole in pharmaceutical tablets using a cathodically pretreated boron-doped diamond electrode. Journal of Electroanalytical Chemistry 707, pp 15–19.... Review al Affiliation Article Review Introduction The article d Differential pulse voltammetric determinationof Albendazole in pharmaceutical tablets using a cathodically pretreated boron-doped diamond electrode by Lourencao, Baccarin, Medeiros, Rocha-Filho & Fatibello-Filho (2013) discusses the use of differential pulse voltammetry (DPV) method on Albendazole...
3 Pages(750 words)Assignment
We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Let us find you another Assignment on topic Chemistry Assignment for FREE!
+16312120006