Chemistry concepts and calculations

1. what is the yei;d of aspirin if the experiment (or actual)yield was 1.850g an

1. what is the yei;d of aspirin if the experiment (or actual)yield was 1.850g and the theoretical yield was 2.0051g? If the synthesized aspirin was found to contain a 10.0%impurit…

1. what volume of a 5% product is required to prepare 900ml of a 1% solution by

1. what volume of a 5% product is required to prepare 900ml of a 1% solution by adding 3% of a product? a) 600ml b) 300ml c) 450ml d) none of the above 2. A prescription for 250ml…

1. when .357 grams of an unkown compound is dissolved in 17.0 grams of benzene,

1. when .357 grams of an unkown compound is dissolved in 17.0 grams of benzene, the freezing point of the solution is depressed by 0.250 degrees C. what is the molar mass of the u…

1. when 1-iodo-1-methycyclohexane is treated with NaOCH2CH3,the more highly subs

1. when 1-iodo-1-methycyclohexane is treated with NaOCH2CH3,the more highly subsituted alkene product predominates. whenKOC(CH3)3 is used, the less highly subsituted alkene produc…

1. when 2-bromo-3-methyl-1-phenylbutane is treated with sodium methoxide, why is

1. when 2-bromo-3-methyl-1-phenylbutane is treated with sodium methoxide, why is the major product 3-methyl-1-butene? A. sn2 predominates over e2 B. the less substituted alkene is…

1. when forming molecular orbitals from atomic orbitals, what is the order of in

1. when forming molecular orbitals from atomic orbitals, what is the order of increasing C-H bond strength for the following. I. sp^3 II. sp^2 III. sp a) II<I<III b) III &lt…

1. which group of elements are found as diatomic molecules (a) alkali metals (b)

1. which group of elements are found as diatomic molecules (a) alkali metals (b) alkaline earth metal (c) halogens (d) noble gas 2. Predict the product when the elements Be(s)+ Br…

1. which group of elements are found as diatomic molecules (a) alkali metals (b)

1. which group of elements are found as diatomic molecules (a) alkali metals (b) alkaline earth metal (c) halogens (d) noble gas 2. Predict the product when the elements Be(s)+ Br…

1. which of the elements attracts electrons more sttrongly? Sodium Oxygen Flouri

1. which of the elements attracts electrons more sttrongly? Sodium Oxygen Flourine Silver 1. What element has the largest atomic radius? Fluorine Iodine Tin Carbon 2.From the foll…

1. which of the following compounds would you expect to be most soluble in H20?

1. which of the following compounds would you expect to be most soluble in H20? CH3F, CCl4, CH4, BF3, CF4 2. Which of the following will produce the lowest osmotic pressure in 0.2…

1. which of the following compounds would you expect to be most soluble in H20?

1. which of the following compounds would you expect to be most soluble in H20? CH3F, CCl4, CH4, BF3, CF4 2. Which of the following will produce the lowest osmotic pressure in 0.2…

1. which of the following is true, NaC 2 H 3 O 2 dissolves spontaneously in H 2

1. which of the following is true, NaC2H3O2 dissolves spontaneously in H2O. temperture drops when the solid dissolves. For this reaction enthalpy and entropy will have the followi…

1. which of the following postulates from Dalton\'s atomic theory was omitted be

1. which of the following postulates from Dalton's atomic theory was omitted because of the later discovery of radioactive elements? a. all matter is made up of very small particl…

1. which of the following substances is the best oxidizing agent? Briefly explai

1. which of the following substances is the best oxidizing agent? Briefly explain your answer. a) Na+ b) Zn c) Li+ d) Ag+ e) Al 2. which of the following substances is the best re…

1. which of the following would be considered a fuel cell? a)C3H8(g) + 5O2(g) --

1. which of the following would be considered a fuel cell? a)C3H8(g) + 5O2(g) --> 3CO2(g) + 4H2O (l) b) Pb(s) + PbO2(s) + 4H^+ (aq) + 2SO4^2-(aq) --> 2PbSO4(s) + 2H2O(l) c) …

1. why brachiopods prefer clear water to muddy waters?? 2. what feature do brach

1. why brachiopods prefer clear water to muddy waters?? 2. what feature do brachiopods and bryozoans have in commom? 3. do you think this type of bryozoan would survive better in …

1. why does olive oil have a lower melting point than butter fat? 2. how does LD

1. why does olive oil have a lower melting point than butter fat? 2. how does LDL differ from HDL's 3. In a helix, how does bond occur between the amino acids in the peptide bond?…

1. why does the mixed aldo condensations producing benzalacetophenone is the mai

1. why does the mixed aldo condensations producing benzalacetophenone is the main reaction in experimet claisen schmidt reaction and not both other possible reaction, acetophenone…

1. why is it not necessary to test the reactivity of the elemental metals with s

1. why is it not necessary to test the reactivity of the elemental metals with solutions of the same metal ion? To illustrate your explanation, write the equation for the potentia…

1. why is lower energy resonance form is more stable than the higher? 2. An aver

1. why is lower energy resonance form is more stable than the higher? 2. An average S–O single bond length is 1.59 Å, and the S=O double bond length is 1.42 Å. For sulfur (third r…

1. would boiling point elevation change if the atmospheric pressure changed duri

1. would boiling point elevation change if the atmospheric pressure changed during the experiment? explain. 2. an unknown compound is suspected to be a group 1 metal/chloride salt…

1. write a shell in C Programming with builtin, that will support the following

1. write a shell in C Programming with builtin, that will support the following commands: A. mycd <directory> - (change the current default directory to <directory>. i…

1. write a shell in C Programming with builtin, that will support the following

1. write a shell in C Programming with builtin, that will support the following commands: A. mycd <directory> - (change the current default directory to <directory>. i…

1. write a shell in C Programming with builtin, that will support the following

1. write a shell in C Programming with builtin, that will support the following commands: A. mycd <directory> - (change the current default directory to <directory>. i…

1. write and balance the equation wuth reacyion of metal with hydrocholric acid:

1. write and balance the equation wuth reacyion of metal with hydrocholric acid: na, al, zn, ca 2. .04250 g of mg is reacted with excess hcl , calculate theoretical volume at stp …

1. write the balance chemical equation for the reaction of KHP with NaOH 2. Supp

1. write the balance chemical equation for the reaction of KHP with NaOH 2. Suppose your laboratory instructor inadvertently gave you a sample of KHP contaminated with NaCL to use…

1. write the empirical formulas for a. H202 b. Al2(SO4)3 c.C4H10 the numbers for

1. write the empirical formulas for    a. H202 b. Al2(SO4)3 c.C4H10 the numbers for the above problem are supposed to be placed below the letters not next to them. 2.white the che…

1. write the reaction of HI in water. 2 .0251 mol of HI is dissolved in enough w

1. write the reaction of HI in water. 2 .0251 mol of HI is dissolved in enough water to make 1.50 L of solution. Calculate the concentrations (molarities) of HI, H3O+ and I- in th…

1. you need to produce a buffer solution that has a pH of 7.00. you already have

1. you need to produce a buffer solution that has a pH of 7.00. you already have a solution that contains 42.0 mmol of NaH2PO4. how many millimeters of Na2HPO4 will you need to ad…

1. you want to prepare an approximately 0.10 M solution of sodium hydroxide. How

1. you want to prepare an approximately 0.10 M solution of sodium hydroxide. How many grams of sodium hydroxide must be added to give you 500 ml of solution? Record this number el…

1.(2 pts) Circle the alkyI halide which would most likely undergo an SN2 and box

1.(2 pts) Circle the alkyI halide which would most likely undergo an SN2 and box the one most likely to undergo an E2- a) b) Br d) e) Br Br 2.(1 pt) Circle the strongest nucleophi…

1.(2 pts) What color photon is absorbed by a solution that appears yellow? 2. (2

1.(2 pts) What color photon is absorbed by a solution that appears yellow? 2. (2 pts) What is the color of a solution if it absorbs photons with a wavelength of 615 nm? 3. (2 pts)…

1.(4 points) Which of the following is not a property of ethers which makes them

1.(4 points) Which of the following is not a property of ethers which makes them good solvents in organic reactions? A) They dissolve a wide range of polar substances. B) They hav…

1.(40 points) Perform the following pressure conversions, assuming when necessar

1.(40 points) Perform the following pressure conversions, assuming when necessary that atmospherie pressure is 1 atm. Unless otherwise stated, the given pressures are absolute. a.…

1.(5 points) A 0.6251 gram sample of acid potassium phthalate (GFW = 204.23) req

1.(5 points) A 0.6251 gram sample of acid potassium phthalate (GFW = 204.23) requires 18.05 mL of a NaOH solution to completely neutralize it using phenolphthalein as an indicator…

1.(5 points) Calculate the concentration (in mM) of a solution prepared by disso

1.(5 points) Calculate the concentration (in mM) of a solution prepared by dissolving 3.02g of solid MgSO4 (Formula Weight: 120.37g/mole) in dH2O (final volume is 50mL)? 2.(15 poi…

1.(5 points) Calculate the concentration (in mM) of a solution prepared by disso

1.(5 points) Calculate the concentration (in mM) of a solution prepared by dissolving 3.02g of solid MgSO4 (Formula Weight: 120.37g/mole) in dH2O (final volume is 50mL)? 2.(15 poi…

1.) (1 port) The norma electron conguration of atom ofandenent is?; A) Bohr\'s m

1.) (1 port) The norma electron conguration of atom ofandenent is?; A) Bohr's model configuration ) the best energy configuration 2) (1 point) Atom ?inOcted state when eledon goes…

1.) 0.962 mol sample of carbon dioxide gas at a temperature of 20.0 °C is found

1.) 0.962 mol sample of carbon dioxide gas at a temperature of 20.0 °C is found to occupy a volume of 21.5 liters. The pressure of this gas sample is_______mm Hg. 2.) A sample of …

1.) 1.35 g H2 is allowed to react with 10.2 g N2, producing 2.95 g NH3. Part A W

1.) 1.35 g H2 is allowed to react with 10.2 g N2, producing 2.95 g NH3. Part A What is the theoretical yield in grams for this reaction under the given conditions? My answer was 7…

1.) 10 mL of 0.1 M NaOH is added to 50 mL of 0.1 M of the hypothetical acid HA.

1.) 10 mL of 0.1 M NaOH is added to 50 mL of 0.1 M of the hypothetical acid HA. write the chemical equation and calculate the molarity of NaA and HA in the final solution. Please …

1.) 10 mL of 0.1 M NaOH is added to 50 mL of 0.1 M of the hypothetical acid HA.

1.) 10 mL of 0.1 M NaOH is added to 50 mL of 0.1 M of the hypothetical acid HA. write the chemical equation and calculate the molarity of NaA and HA in the final solution. Please …

1.) 2.) 3.) 4.) The combustion reaction of ethane is as follows. C2H6(g) + 7/2 O

1.) 2.) 3.) 4.) The combustion reaction of ethane is as follows. C2H6(g) + 7/2 O2(g) rightarrow 2 CO2(g) + 3 H2O(I) Using Hess's law and the reaction enthalpies given below, find …

1.) 2.) 6.) (two parts) The half-life of radium-226 is 1.60 x 103 yr. How many h

1.) 2.) 6.) (two parts) The half-life of radium-226 is 1.60 x 103 yr. How many hours will it take for a 2.50-g sample to decay to the point where 0.185 g of the isotope remains? E…

1.) 2A B + C The above reaction is run and found to follow second order kinetics

1.) 2A B + C The above reaction is run and found to follow second order kinetics with a rate constant of 1.30 x 10-3 M-1sec-1. If the initial concentration of A is 1.33 M, what is…

1.) 4HCl(g)+O2(g)====>2Cl2(g)+2H2O(g) Calculate the number of grams of Cl2 forme

1.) 4HCl(g)+O2(g)====>2Cl2(g)+2H2O(g) Calculate the number of grams of Cl2 formed when 0.470 mol HCl react with O2. 2.) 2KClO3====>2KCl+3O2 If this reaction produced 97.2 g …

1.) 50 mL of an unknown monoprotic weak acid was titrated with 0.1 M NaOH and th

1.) 50 mL of an unknown monoprotic weak acid was titrated with 0.1 M NaOH and the results below were obtained. a.What is the concentration of the weak acid?_______________________…

1.) A 0.062 M aqueous sample of species y was analyzed by atomic absorption spec

1.) A 0.062 M aqueous sample of species y was analyzed by atomic absorption spectroscopy at 525 nm and in a 1.00-cm cell and yielded a %T value of 70.19 % . Calculate the molar ab…

1.) A 1.75 mol sample of Xe gas is confined in a 42.4 liter container at 22.6 °C

1.) A 1.75 mol sample of Xe gas is confined in a 42.4 liter container at 22.6 °C. If the temperature of the gas sample is decreased to 4.90 °C, holding the volume constant, the pr…

1.) A 10g example of an oxide of copper when heated in a stem of hydrogen forms

1.) A 10g example of an oxide of copper when heated in a stem of hydrogen forms 1.26g of water. What is % of copper by mass in the compound? 2.) A sample of ammonium dichromate co…