CHM 152 NAU Chemistry discussion questions

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hey there, plz solve each Question in file plz.

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1) How many grams of beryllium chloride are needed to make 125 mL of a 0.050 M solution?

2) How many grams of beryllium chloride would you need to add to 125 mL of water to make a 0.050 molal solution?

3) The density of ethanol is 0.789 g/mL.  How many grams of ethanol should be mixed with 225 mL of water to make a 4.5% (v/v) mixture?

4) Explain how to make at least one liter of a 1.25 molal ammonium hydroxide solution.

5) What is the molarity of a solution in which 0.45 grams of sodium nitrate are dissolved in 265 mL of solution

Concentration Calculations – CHM 152 Name Please show work on separate sheets of paper. 1) How many grams of beryllium chloride are needed to make 125 mL of a 0.050 M solution? 2) How many grams of beryllium chloride would you need to add to 125 mL of water to make a 0.050 molal solution? 3) The density of ethanol is 0.789 g/mL. How many grams of ethanol should be mixed with 225 mL of water to make a 4.5% (v/v) mixture? 4) Explain how to make at least one liter of a 1.25 molal ammonium hydroxide solution. 5) What is the molarity of a solution in which 0.45 grams of sodium nitrate are dissolved in 265 mL of solution. 6) If I add 25 mL of water to 125 mL of a 0.15 M NaOH solution, what will the molarity of the diluted solution be? 7) If I add water to 100 mL of a 0.15 M NaOH solution until the final volume is 150 mL, what will the molarity of the diluted solution be? 8) How much 0.05 M HCl solution can be made by diluting 250 mL of 10 M HCl? 9) I have 345 mL of a 1.5 M NaCl solution. If I boil the water until the volume of the solution is 250 mL, what will the molarity of the solution be? 10) How much water would I need to add to 500 mL of a 2.4 M KCl solution to make a 1.0 M solution? 11) If I make a solution by adding 83 grams of sodium hydroxide to 750 mL of water… 12) a) What is the molality of sodium hydroxide in this solution? b) What is the percent by mass of sodium hydroxide in this solution? If I make a solution by adding water to 35 mL of methanol (CH3OH) until the final volume of the solution is 275 mL… a) What is the molarity of methanol in this solution? (The density of methanol is 0.792 g/mL) b) What is the percent by volume of methanol in this solution? 13) Explain why chemical compounds tend to dissolve more quickly in hot solvent than in cold solvent. 14) Give an example of two liquids that are immiscible. Concentration Calculations – CHM 152 Name 15) What is the molarity of a solution made when you dilute 35 grams of sodium carbonate to a volume of 3,400 mL? 16) Explain how you would make 450 mL of a 0.25 M calcium chloride solution. 17) Glucose is a sugar that is found abundantly in nature. What is the percent by mass of a solution made by dissolving 163 g of glucose in 755 g of water? Do you need to know the formula of glucose? Why or why not? 18) What is the mass percent sucrose in a solution obtained by mixing 225 g of an aqueous solution that is 6.25% sucrose by mass with 135 g of an aqueous solution that is 8.20% sucrose by mass? 19) Determine the volume percent of toluene in a solution made by mixing 40.0 mL toluene with 75.0 mL of benzene. 20) What is the concentration of Na+, in parts per million by mass, in 0.00152 M Na2SO4? 21) What is the molality of a solution prepared by dissolving 225 mg of glucose (C6H12O6) in 5.00 mL of ethanol (density = 0.789 g/mL) 22) How many milliliters of water (density = 0.998 g/mL) are required to dissolve 25.0 g of urea (CO(NH2)2) in order to produce a solution that is 1.65 m? (m is the abbreviation for molality) 23) Describe the process you would use in order to prepare 5.00 kg of an aqueous solution that is 8.00% NaCl by mass. 24) What is the mass percent of solute when 4.12 g is dissolved in 100.0 g of water? 25) What is the volume percent of 10.00 g of acetone (d = 0.789 g/mL) in 1.55 L of an acetone-water solution? 26) On average, glucose makes up about 0.10% of human blood, by mass. What is the approximation concentration of glucose in blood in milligrams per deciliter?. 27) Convert 0.0035% NaCl by mass into parts per million of NaCl. 28) Convert 2.4 ppm F- into molarity of fluoride ion. 29) Calculate the molality of a solution prepared by dissolving 125 mL of pure methanol (density = 0.791g/mL) into 275 g of ethanol.
Homework 5 Show all of your work 1. The following is data for the reaction: N2O5 NO3 + NO2 Time (sec) [N2O5] (M) 0 1.00 25 0.822 50 0.677 75 0.557 100 0.458 125 0.377 150 0.310 Plot 3 graphs in Excel showing [N2O5] v. time, ln [N2O5] v. time, and 1/[N2O5] v. time. (if you don’t have Excel you can use any graphing program, or the computers on campus to plot and determine the order of the reaction with respect to N2O5 A. What is the order of the reactant N2O5? B. Write the rate law for the reaction. C. What is the value of the rate constant, k? D. What would the concentration be at 500 seconds E. What is the half-life for this reaction? F. How much N2O5 would be left after 7 half-lives? Homework 4: Chemical Kinetics, Part 2 Show all of your work 2. The following is data for the reaction: C4H8  2 C2H4 Time (sec) [C4H8] (M) 0 1.00 10 0.894 20 0.799 30 0.714 40 0.638 50 0.571 60 0.510 Plot 3 graphs in Excel showing [C4H8] v. time, ln [C4H8] v. time, and 1/[C4H8] v. time. (if you don’t have Excel you can use any graphing program, or the computers on campus to plot and determine the order of the reaction with respect to N2O5 A. What is the order of the reactant C4H8? B. Write the rate law for the reaction. C. What is the value of the rate constant, k? D. What would the concentration be at 110 seconds E. What is the half-life for this reaction? F. How much C4H8 would be left after 5 half-lives? G. How long would it take to get through 5 half-lives of this reaction. 3. Write the rate law for the reaction below without any experimental data. Homework 4: Chemical Kinetics, Part 2 Show all of your work Cl2 (g) + 2 NO (g) → 2 NOCl (g) 4. The hydrolysis of tert-butyl chloride is given in the reaction below: (CH3)3CCl (aq) + H2O (l) → (CH3)3COH (aq) + H+ (aq) + Cl- (aq) If the rate law is: rate = k[(CH3)3CCl], what is the order of the reaction with respect to water? 5. What is the overall order of the reaction that has the rate law: rate = k[H2][NO]2 ? 6. The following set of data was obtained by the method of initial rates for the reaction: 2 HgCl2 (aq) + C2O4 2- (ag) → 2 Cl- (aq) + 2 CO2 (g) + Hg2Cl2 (s) What is the rate law for the reaction? What is the value of the rate constant? What is the overall order? [HgCl2], M 0.10 0.10 0.20 [C2O42-],M 0.10 0.20 0.20 Rate, M/s 1.3 x 10-7 5.2 x 10-7 1.0 x 10-6 7. For a particular first order reaction, it takes 48 minutes for the concentration of the reactant to decrease to 25% of its initial value. What is the value for the rate constant (in s-1 ) for the reaction? 8. The rate constant for a first order reaction is equal to 4.2 x 10-4 s -1 . What is the half-life for the reaction? Homework 4: Chemical Kinetics, Part 2 Show all of your work 9. A plot of 1 / [BrO- ] vs. time is linear for the reaction: 3 BrO- (aq) → BrO3 - (aq) + 2 Br- (aq) What is the order of the reaction with respect to the hypobromite ion? 10. The following is data for the reaction: N2O5  2 NO2 + ½ O2 T (K) k 338 4.87x10-3 328 1.50 x10-3 318 4.98 x10-4 308 1.35 x10-4 298 3.46 x10-5 273 7.87 x10-7 Calculate the activation energy of this reaction. (this is an Arrhenius equation problem) You need to graph this data as ln k v 1/T Use this linear form of the equation: ln k = -Ea / RT + ln A (y = mx = b) and your graph to determine the Energy of Activation. Use the text to help.
CHM 152 Homework 4 Chemical Kinetics 1. For the reaction given below, what is the instantaneous rate of reaction for each of the reactants and products? 3A + 2B  4C 2. Given the following experimental data, find the rate law and the rate constant for the reaction: NO (g) + NO2 (g) + O2 (g)  N2O5 (g) Run [NO]o , M [NO2[o , M [O2]o , M Initial Rate, Ms-1 1 0.10 M 0.10 M 0.10 M 2.1 x 10-2 2 0.20 M 0.10 M 0.10 M 4.2 x 10-2 3 0.20 M 0.30 M 0.20 M 1.26 x 10-1 4 0.10 M 0.10 M 0.20 M 2.1 x 10-2 CHM 152 Homework 3 Chemical Kinetics 3. The following data give the concentration of gaseous butadiene as a function of time at 500 K. Determine the order of the reaction, and the value of the rate constant. t(sec) C(moles/liter) 195 604 1246 2180 4140 4655 6210 8135 1.62 x 10-2 1.47 x 10-2 1.29 x 10-2 1.10 x 10-2 0.89 x 10-2 0.80 x 10-2 0.68 x 10-2 0.57 x 10-2 4. For the chemical reaction AB it is found that the rate of the reaction doubles when the concentration of A is increased four times. The order with respect to ‘A’ for this reaction is: 5. The rate of a reaction between A and B increases by a factor of 100, when the concentration of A is increased 10 folds. The order of the reaction with respect to A is: CHM 152 Homework 3 Chemical Kinetics 6. For the reaction, 2 N2O5(g)  4 NO2(g) + O2(g), the rate of formation of NO2(g) is 4.0 x 10-3 mol L-1s-1. (a) Calculate the rate of disappearance of N2O5(g) (b) Calculate the rate of appearance of O2(g). 7. The reaction 2 NO(g) + 2 H2(g)  N2(g) + 2 H2O(g) is found experimentally to be second order in NO(g) and first-order in H2(g). (a) Write the rate law for the reaction. (b) What is the overall order of the reaction? (c) What are the units for the rate constant k? (d) If [NO] is doubled (while keeping [H2] constant), by what factor will the reaction rate increase? (e) If [H2] is doubled (while keeping [NO] constant), by what factor will the reaction rate increase? CHM 152 Homework 3 Chemical Kinetics 8. Kinetic Data for the Peroxydisulfate Reaction at 20.0 oC Experiment # [S2O8-2] (M) [I-] (M) 1 2 3 0.200 0.400 0.400 0.200 0.200 0.400 Initial Rate of Reaction (M x s1 ) 2.2 x 10-3 4.4 x 10-3 8.8 x 10-3 a. Determine the order of the reaction with respect to [S2O8-2]. b. Determine the order of the reaction with respect to [I-]. c. Determine the overall order of the reaction. d. Write the rate law expression for the reaction. e. What is the value for the rate constant, K? 9. The results from four experiments to study the reaction: BrO3- + 5Br- + 6H+  3Br2 + 3H2O Experiment # Initial Initial Initial Measure Concentration Concentration Concentration d Initial of BrO3of Brof H+ Rate (M x s-1) 1 0.10 M 0.10 M 0.10 M 8.0 x 10-4 2 0.20 M 0.10 M 0.10 M 1.6 X 10-3 3 0.20 M 0.20 M 0.10 M 3.2 x 10-3 4 0.10 M 0.10 M 0.20 M 3.2 x 10-3 a. Determine the order of the reaction with respect to [BrO3-]. b. Determine the order of the reaction with respect to [Br-]. CHM 152 Homework 3 Chemical Kinetics c. Determine the order of the reaction with respect to [H+]. d. Determine the overall order of the reaction. e. Write the rate law expression for the reaction. f. What is the value for the rate constant, K? 10. What are two reasons (according to collision theory) that the rates of most reactions increase with increasing temperature?
CHEM 152 Homework 3 Physical Properties of Solutions 1. To determine the molar mass of a certain protein, 1.00 × 10−3 g of it was dissolved in enough water to make 1.00 mL of solution. The osmotic pressure of this solution was found to be 1.12 torr at 25.0°C. Calculate the molar mass of the protein. 2. What concentration of sodium chloride in water is needed to produce an aqueous solution isotonic with blood (π = 7.70 atm at 25°C)? 3. The observed osmotic pressure for a 0.10 M solution of Fe(NH4)2(SO4)2 at 25°C is 10.8 atm. Compare the expected and experimental values for i. 4. What is the total ion molarity of a 0.15 M solution of K3PO4. 5. What is the molality of a solution of 1.25 moles of sugar dissolved in 0.750 kg of water? 6. What is the freezing and boiling point of the solution in Q 15? [For water as the solvent, kb=0.512oC/m; kf = 1.86 oC/m] 7. Pure toluene (C7H8) has a normal boiling point of 110.60oC. A solution of 7.80 g of anthracene (C14H10), in 100.0 g.toluene has a boiling point of 112.06oC. a. What is the molality of the solution? b. What is the molal boiling point elevation constant for toluene?  8.. 'HILQHHDFKRIWKHIROORZLQJWHUPV DHOHFWURO\WH EFROOLJDWLYHSURSHUW\ FVDWXUDWHGVROXWLRQ A solution of JRIDGUHQDOLQHLQJRI&&O4 SURGXFHVDESHOHYDWLRQRI°&:KDWLV DGUHQDOLQH VPROHFXODUZHLJKW  1$n aqueous solution of trichloroacetic acid, HC2Cl3O2, has a concentration of 3.92 mol/L and a density of 1.280 g/mL. Calculate the mole fraction of HC2Cl3O2 in the solution.

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Tutor went the extra mile to help me with this essay. Citations were a bit shaky but I appreciated how well he handled APA styles and how ok he was to change them even though I didnt specify. Got a B+ which is believable and acceptable.

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