Chemistry concepts and calculations

1)A slightly bruised apple will rot extensively in about four days at room tempe

1)A slightly bruised apple will rot extensively in about four days at room temperature (25oC). If it is kept in a refrigerator at 4oC, the same extent of rotting takes about fifte…

1)A solid mixture consists of 25.5 g of KNO3 (potassium nitrate) and 4.5 g of K2

1)A solid mixture consists of 25.5 g of KNO3 (potassium nitrate) and 4.5 g of K2SO4 (potassium sulfate). The mixture is added to 130. g of water. If the solution described in the …

1)A solution contains 8.65×10 -3 M silver acetate and 9.83×10 -3 M chromium(III)

1)A solution contains 8.65×10-3 M silver acetate and 9.83×10-3 M chromium(III) nitrate. Solid sodium hydroxide is added slowly to this mixture. A. What is the formula of the subst…

1)A solution is prepared by mixing 50.0 mL of 0.33 M Pb(NO 3 ) 2 with 50.0 mL of

1)A solution is prepared by mixing 50.0 mL of 0.33 M Pb(NO3)2 with 50.0 mL of 1.0 M KCl. Calculate the concentration of Cl- at equilibrium, Ksp for PbCl2(s) is 1.6 × 10-5. 2)Calcu…

1)A spring can exert what kind of forces if all different sizes. How can it be s

1)A spring can exert what kind of forces if all different sizes. How can it be said to have a spring constant, also called a stiffness constant or force or k value or Hookes-law c…

1)A student carried out a simple distillation on a compound known to distill at

1)A student carried out a simple distillation on a compound known to distill at 124°C and reported a boiling point range of 116-117°C. Gas chromatographic analysis of the product …

1)A student purified the acetanilide by using recrystalization experiment and he

1)A student purified the acetanilide by using recrystalization experiment and he got the following results. Based on the following results answer the questions. Starting weight of…

1)A student separates a 3.50 g sample of an unknown mixture of benzoic acid, 4-n

1)A student separates a 3.50 g sample of an unknown mixture of benzoic acid, 4-nitroaniline, and benzil using an acid-base extraction procedure. After the separation, the student …

1)A volume of 105 mL of H2O is initially at room temperature (22.00 C). A chille

1)A volume of 105 mL of H2O is initially at room temperature (22.00 C). A chilled steel rod at 2.00 C is placed in the water. If the final temperature of the system is 21.40 C , w…

1)A well known aphorism in chemistry is that for every 10° increase in temperatu

1)A well known aphorism in chemistry is that for every 10° increase in temperature, the rate of a reaction will increase twofold. If the reaction were performed at 45° C predict w…

1)Aluminum reacts with bromine to produce aluminum bromide. How any moles of bro

1)Aluminum reacts with bromine to produce aluminum bromide. How any moles of bromine are required to react with 3.53 moles of aluminum? Record your answer to two (2) decimal place…

1)Another metal phosphate is aluminum phosphate. It will behave similar to calci

1)Another metal phosphate is aluminum phosphate. It will behave similar to calcium phosphate in an acid solution. What is the net ionic equation including phases for AlPO4(s) diss…

1)Answer the following questions. What is the effective nuclear charge for stron

1)Answer the following questions. What is the effective nuclear charge for strontium. Calculation: Z* = = What is the effective nuclear charge for chlorine. Calculation: Z* = = Wh…

1)Arrange these ions in order of increasing ionic radius: K+ , P3– , S2– , Cl– .

1)Arrange these ions in order of increasing ionic radius: K+ , P3– , S2– , Cl– . Increasing radius --- > 2)Which of the following elements has the largest first ionization ener…

1)Boron trichloride is prepared from the following reaction. 2B 2 O 3 + 6Cl 2 +

1)Boron trichloride is prepared from the following reaction. 2B2O3 + 6Cl2 + 3C --> 4BCl3 + 3CO2 If 8.254g of B2O3 is mixed with 4.446g of Cl2 and 4.115g of C then answer the fo…

1)Boston Harbor The Massachusetts Water Resources Authority (MWRA) claims that t

1)Boston Harbor The Massachusetts Water Resources Authority (MWRA) claims that the $3.8 billion dollar Boston Harbor Cleanup has been a great success. a.) Please present evidence …

1)Calculate the final concentration of each of the following: 2.6 L of a 5.0 M H

1)Calculate the final concentration of each of the following: 2.6 L of a 5.0 M HCl solution is added to water so that the final volume is 7.0 L . Cfinal = ? M Water is added to 0.…

1)Calculate the free energy %u0394G (in kJ/mol) for a reaction 4A + 3 B %u21CC 1

1)Calculate the free energy %u0394G (in kJ/mol) for a reaction   4A + 3 B   %u21CC 1 C + 3 D knowing that the concentrations are: [A] = 0.78 M,   [B] = 1.49 M,   [C] = 0.5 M,   [D…

1)Calculate the grams or milliliters of solute needed to prepare the following s

1)Calculate the grams or milliliters of solute needed to prepare the following solutions. 65. g of a 8.0 % (m/m) KCl solution Answer should be in Grams. 1150 mL of a 3.0 % (m/v) N…

1)Calculate the hydronium ion concentration and the pH of the solution that resu

1)Calculate the hydronium ion concentration and the pH of the solution that results when 10.6 mL of 0.21 M acetic acid, is mixed with 6.9 mL of 0.060 M NaOH. Hydronium ion concent…

1)Calculate the molarity of each of the following solutions. 0.30 mol of LiNO3 i

1)Calculate the molarity of each of the following solutions. 0.30 mol of LiNO3 in 6.32 L of solution Express your answer using two significant figures. 2) What is the net ionic eq…

1)Calculate the number of moles of nitrogen dioxide, NO2, that could be prepared

1)Calculate the number of moles of nitrogen dioxide, NO2, that could be prepared from 62.0 mol of nitrogen oxide and 74.0 mol of oxygen. 2NO(g)+O2(g)? 2NO2(g) --------------------…

1)Calculate the partial pressure (in atm) of Br 2 at equilibrium when 2.35 atm o

1)Calculate the partial pressure (in atm) of Br2 at equilibrium when 2.35 atm of C2H5Br and 2.35 atm of HBr react at 2500 K according to the following chemical equation: Report yo…

1)Calculate the partial pressure (in atm) of H 2 at equilibrium when 3.49 atm of

1)Calculate the partial pressure (in atm) of H2 at equilibrium when 3.49 atm of CO and 5.63 atm of H2O react at 1000 K according to the following chemical equation: Report your an…

1)Calculate the rate constant k , given that k ¢ = k ×[I - ]. Include the units

1)Calculate the rate constant k, given that k¢ = k×[I-]. Include the units and indicate the temperature. The concentration of KI from the previous experiment =0.4 M . Therefore th…

1)Chemically, what takes place when a car battery is discharged and recharged? W

1)Chemically, what takes place when a car battery is discharged and recharged? What other power sources transfer power through chemical reactions? Provide a brief description of h…

1)Chlorine has two stable isotopes. The first isotope has a mass number 35 and i

1)Chlorine has two stable isotopes. The first isotope has a mass number 35 and is present 75.77% of the time. The second isotope has a mass number of 37. Calculate their molar mas…

1)Choose the packing scheme that gives the highest density of spheres. Simple cu

1)Choose the packing scheme that gives the highest density of spheres. Simple cubic packing Trigonal close packing Hexagonal close packing Body-centered cubic packing 2)Choose the…

1)Consider the decomposition of hydrogen peroxide into liquid water and oxygen g

1)Consider the decomposition of hydrogen peroxide into liquid water and oxygen gas: 2 H202 (AQ) -> 2H20 (L) + 02 (G) A) HOW MANY OF EACH OF THE PRODUCT MOLECULES WILL BE FORMED…

1)Consider the following balanced redox reaction in acidic medium: 2Cr(OH)3 (s)

1)Consider the following balanced redox reaction in acidic medium: 2Cr(OH)3 (s) + 6ClO- (aq) + 2H+ (aq) ---> 2CrO4^2- (aq) + 3Cl2 (g) a) What is the oxidizing agent? b) Which e…

1)Consider the following disaccharides and say which one is not a reducing sugar

1)Consider the following disaccharides and say which one is not a reducing sugar. glucose-2-2-fructose glucose-1-4-fructose galactose-2-4-glucose glucose-1-6-glucose 2)Carbohydrat…

1)Consider the following equilibrium: PCl3 (g) + Cl2 (g) PCl5 (g) Kc = 26 at 250

1)Consider the following equilibrium: PCl3 (g) + Cl2 (g) PCl5 (g) Kc = 26 at 250°C 1.0 mol of PCl3, 1.0 mol of Cl2, and 5.0 mol of PCl5 are placed in a 10.0 L flask at 250°C and a…

1)Consider the following reaction and associated equilibrium constant: a A( g )

1)Consider the following reaction and associated equilibrium constant: aA(g)bB(g), Kc = 3.4 Find the equilibrium concentrations of A and B for a = 2 and b = 1. Assume that the ini…

1)Consider the following reaction: 2 HI (g) H? (g) + I? (g) When 4.00 moles

1)Consider the following reaction:                                2 HI (g) <=> H? (g) + I? (g) When 4.00 moles of HI were put on a container of 5.00 L at 458 degrees, we fou…

1)Consider the following statements regarding the processes of fluorescence and

1)Consider the following statements regarding the processes of fluorescence and phosphorescence. Determine whether each statement is true for fluorescence only, true for phosphore…

1)Consider the reaction when aqueous solutions of magnesium nitrate and cobalt(I

1)Consider the reaction when aqueous solutions of magnesium nitrate and cobalt(II) sulfate are combined. What is the net ionic equation?     2) For the following reaction, 48.8 gr…

1)Create a conditional expression that evaluates to string \"negative\" if userV

1)Create a conditional expression that evaluates to string "negative" if userVal is less than 0, and "positive" otherwise. Example output when userVal = -9 for the below sample pr…

1)Describe the process you would go through to find the number of valence electr

1)Describe the process you would go through to find the number of valence electrons for any of the main group (columns 1-8) elements.2) Although both sugar and salt are soluble in…

1)Describe the relationship of the law of conversation of mass and to radioactiv

1)Describe the relationship of the law of conversation of mass and to radioactive decay process 2describe sources of radioactivity in the human environment 3) which source of radi…

1)Determine the limiting reactant. Express your answer as a chemical formula. 2)

1)Determine the limiting reactant. Express your answer as a chemical formula. 2) Determine the theoretical yield of urea Express your answer using four significant figures. 3) Det…

1)Determine the molarity (in mol/L) of NH 4 + ions in solution when 3.60×10 -2 g

1)Determine the molarity (in mol/L) of NH4+ ions in solution when 3.60×10-2 g of ammonium oxalate is added to enough water to prepare 5.23×102 mL of the solution 2)Calculate the m…

1)Determine the number of electrons formally transferred in the balanced equatio

1)Determine the number of electrons formally transferred in the balanced equation . 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g) 2)Given the balanced equation, for the species that forms as…

1)Dextran is a polymetric carbohydrate produced by certain bacteria .It is used

1)Dextran is a polymetric carbohydrate produced by certain bacteria .It is used as a blood plasma substitute . An aqueous solution contains 0.582 g of dextran in 106 ml of solutio…

1)Do you need a special kind of business license to do business online? 2)As an

1)Do you need a special kind of business license to do business online? 2)As an online business, do you have to be concerned with applicable laws in the jurisdictions that you are…

1)Drug X binds to two sites (S-1 & S-2 where the former is associated with the t

1)Drug X binds to two sites (S-1 & S-2 where the former is associated with the therapeutic effect and the latter with an adverse effect) with a 10-fold difference in affinity …

1)Drug X binds to two sites (S-1 & S-2 where the former is associated with the t

1)Drug X binds to two sites (S-1 & S-2 where the former is associated with the therapeutic effect and the latter with an adverse effect) with a 10-fold difference in affinity …

1)During the course of this experiment you will need to use the same glassware t

1)During the course of this experiment you will need to use the same glassware to transfer liquids of different concentrations. To avoid contaimination, the pipettes used will be …

1)Enter the complementary sequence to the following DNA strand. TGACGTGAT ? 2)Gi

1)Enter the complementary sequence to the following DNA strand. TGACGTGAT ? 2)Given the DNA template strand 3' AACAGACAG 5', write the amino acid sequence in the N-terminal to C-t…

1)Enter the complementary sequence to the following DNA strand. TGACGTGAT ? 2)Gi

1)Enter the complementary sequence to the following DNA strand. TGACGTGAT ? 2)Given the DNA template strand 3' AACAGACAG 5', write the amino acid sequence in the N-terminal to C-t…

1)Ethane from Marcellus shale gas is burned in a furnace at the rate of 200 m 3

1)Ethane from Marcellus shale gas is burned in a furnace at the rate of 200 m3/min. The furnace uses 10% excess air. a)What would be air flow rate in m3/h? b)The ambient temperatu…