Solutions Questions and Answers

A certain Iuld X has a normal freezing point of 2.00 °C and a freezing point depression constant K, 6.08 °C-kg mol. Calculate the freezing point of a solution made of 35.3 g of sodium chloride (NaCl) dissolved in 650. g of X. Round your answer to 2 significant digits.

During an experiment, 29.23g of NaCl is completely dissolved in 2000 ml water. What is the molarity (M) of this NaCl solution? (Show the mathematical calculations and circle the correct answer)

Two 20.0 g ice cubes at -11.0 °C are placed into 285 g of water at 25.0 °C. Assuming no energy is transferred to or from the surroundings, calculate the final temperature, Tr, of the water after all the ice melts. heat capacity of H₂O(s) heat capacity of H₂O(1) enthalpy of fusion of H₂O 37.7 J/(mol-K) 75.3 J/(mol-K) 6.01 kJ/mol T₁=

Calculate the number of moles of solute in 38.29 mL of 0.1275 M K., Cr₂O, (aq). moles of solute:

Consider the following reaction: 6Li (s) + N, (g) → 2Li₂N (s) If 4.00 g N, (g) reacts with excess lithium, then calculate the theoretical yield of lithium nitride. A) Theoretical Yield= [Select] B) If 3.20 g of product forms, then what is the percent yield? = [Select] %

Calculate the mass (in grams) of KHP you will use to titrate with NaOH. Assume that you want the equivalence point to be at about 25 mL of added NaOH, since you are using a 50 mL buret and want to record the entire titration curve like you did with the nitric acid titration. Get this value checked by your instructor before you proceed.

A chemist prepares a solution of zinc oxalate (ZnC₂04) by measuring out 0.0032 μmol of zinc oxalate into a 450. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in µmol/L of the chemist's zinc oxalate solution. Round your answer to 2 significant digits. μmol L X S ?

Calculate the solubility at 25 °C of PbCO3 in pure water and in a 0.0190 M Pb(NO3), solution. You'll find K,, data in the ALEKS Data tab. P Round both of your answers to 2 significant digits. solubility in pure water: solubility in 0.0190 M Pb(NO₂)₂ solution: 7.2 x 10 1.0 X 10 L 0.9 0x0 X G 00 g 2

If 113 mL of an aqueous solution containing 2.33 g of vanillin is extracted with 64 mL of an organic solvent which is then dried, how much vanillin would be recovered? Assume Kow = 10.3. Report your answer to two decimal places.

1. A compound has a mass of 45.632 grams was added to 500.0 ml of water with an initial temperature of 26.7 °C. After thorough mixing, the temperature decreases to 24.1 °C. How many calories were transferred? Is this an exothermic or endothermic process? Heat = (mass solution (AT)

42.7 mL of a solution of sulfuric acid (H₂SO4) of unknown concentration is titrated to its equivalence point with 38.5 mL of a 0.256 M solution of sodium hydroxide. What was the concentration of sulfuric acid? 0.256 M 0.427 M 0.214 M 0.115 M 0..230 M 0.460 M

Calculate the concentration of a solution made by diluting 71.0 mL of 3.0 M HBr to a final volume of 700.0 mL. Significant figures are graded for this problem. Be sure you do not round your answers until the very end of your calculations. concentration: M

Practice Problem 3: An antacid tablet (Tums) was dissolved in 26.00 mL of 0.650 M HCl. The excess acid was back-titrated with exactly 11.34 mL of 1.05 M NaOH. Calculate the moles of HCl neutralized by the tablet, the moles of CaCO3 reacted and the mass of CaCO3 per tablet (in mg).

A 3.405 M solution contains 205 g of H₂SO4. What is the volume of the solution? • Report your answer using three significant figures.

What volume (in mL) of a 0.113 M NaCl solution contains 0.087 mol NaCl? • Report your answer with two significant figures. Provide your answer below: mL

Calculate the volume of a stock solution of Ba(OH)2, with a concentration of 0.10 M, needed to prepare 7.0 L of 0.095 M Ba(OH)₂. Select the correct answer below: 0.67 L 0 74L ( 6.7 L 0.95 L

The formula that governs the concentration of gas dissolved in a solvent based on its pressure is given by Henry's Law: C = KP Where: C = solubility of a gas at a fixed temperature (in mol/L, M) k = Henry's Law constant (in units of mol/L atm) P = partial pressure of the gas (in units of atm) How many grams of carbon dioxide gas is dissolved in a 250-mL can of cola if the manufacturer uses a pressure of 2.9 atm in the bottling process at 25°C ? Assume that the k of CO₂ in water = 0.034 mol/L atm) at 25°C. Report your answer to two significant figures.

Suppose a 0.48 M aqueous solution of oxalic acid (H₂C₂O4) is prepared. Calculate the equilibrium molarity of C₂0₁₂ You'll find information on the properties of oxalic acid in the ALEKS Data resource. Round your answer to 2 significant digits. M

(optional) Mercury chloride is a fungicide. If the molar mass of the fungicide is 470 g/mol and the percent composition is 85.0% Hg and 15.0 % Cl, what is the empirical formula and molecular formula of the compound? Empirical formula Molecular formula

What mass of solute is required to produce 424.4 mL of a 0.191 Msolution of KBr? g KBr What mass of NaNO3 is required to prepare 16.2 mL of solution of NaNO3 with a molarity of 0.249 M? g NaNO3 What mass of CH3OH is required to prepare 109.7 mL of solution with a CH3OH concentration of 0.342 M? g CH3OH 1.202

A chemist dissolves 544. mg of pure barium hydroxide in enough water to make up 200. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Round your answer to 3 significant decimal places.

A chemist must prepare 500.0 mL of potassium hydroxide solution with a pH of 12.90 at 25 °C. He will do this in three steps: • Fill a 500.0 mL volumetric flask about halfway with distilled water. •Weigh out a small amount of solid potassium hydroxide and add it to the flask. •Fill the flask to the mark with distilled water. Calculate the mass of potassium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits.

A chemist must prepare 600.0 mL of potassium hydroxide solution with a pH of 12.50 at 25 °C. He will do this in three steps: • Fill a 600.0 mL volumetric flask about halfway with distilled water. • Weigh out a small amount of solid potassium hydroxide and add it to the flask. •Fill the flask to the mark with distilled water. Calculate the mass of potassium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits. .

A chemist must prepare 800.0 mL of sodium hydroxide solution with a pH of 13.00 at 25 °C. She will do this in three steps: Fill a 800.0 mL volumetric flask about halfway with distilled water. Weigh out a small amount of solid sodium hydroxide and add it to the flask. Fill the flask to the mark with distilled water. Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits. . . .

A chemist dissolves 373. mg of pure sodium hydroxide in enough water to make up 110. ml. of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.) Round your answer to 3 significant decimal places.

Julie has been asked to measure the concentration of a sample solution using a spectrophotometer. After a first attempt, she realizes that, to make the measurement, she must first dilute the sample solution. Julie transfers 2.0 mL of the sample to a 250 mL volumetric flask and fills the rest of the flask with water to the 250 mL line. She then uses the spectrophotometer to measure the concentration of the dilute solution as 7.9 x 10-5 M. What is the concentration of the starting sample solution?

A concentrated solution of 0.481 M beryllium acetate is used to make a dilute solution with an acetate ion concentration of 0.117 M. The dilute solution is prepared by removing 186. mL of 0.481 M beryllium acetate and diluting it by adding water to make a 0.117 M acetate ion concentration. What is the total volume of the dilute solution? (A) 22.6 mL (B) 1. 53 x 10³ mL (C) 45. 1 mL (D) 1. 63 x 103 mL (E) 1. 42 x 103 mL

Solid sodium reacts with liquid water to form hydrogen gas according to the equation 2 Na(s) + 2 H₂O(1)→ 2 NaOH(aq) + H₂(g) What is the pressure (in atm) of hydrogen gas in the 20.0 L headspace of a reactor vessel when 1.00 kg sodium is reacted with excess water at 50.0°C?

You prepare a stock solution (highly concentrated) of sugar in water whose concentration is 500 g/L. You need to make a new solution that is half (1/2) as concentrated and has a final volume of 100 ml. Describe how you would make this dilution. (3 points) Hint: You can use the C,V₁ = C₂V₂ formula discussed at the end of last week's lab. Step one: Your new solution has a concentration of Step two: To make 100 ml of this new solution, you will need to add stock solution plus_ of water. of concentrated Hint: Calculate your volume based on your stock solution. Water is a 'filler that you add to reach final volume. Now make a second solution that is one-tenth (1/10) as concentrated as the initial stock solution and has a final volume of 100 ml. Describe how you would make this dilution. Step one: Your new solution has a concentration of Step two: To make 100 ml of this new solution, you will need to add stock solution plus of water. of concentrated

What is the percent composition of H in C9H16?

Calculate the mass percent of a sucrose solution that is made by mixing 6.420 grams of sucrose into water until the solution has a mass of 29.1 grams. Show your work:

Calculate the concentration in ppm of lead in a solution that contains 69.32 mg Pb per 3.35 kg of solution.

What is the concentration of magnesium bromide, in ppm, if 136.1 g MgBr₂ dissolved in 2.94 L

A substance is at a temperature of 25 °F. What is the temperature of the substance in degrees Celsius (to the nearest who degree)? Select the correct answer below: -34 °C -42 °C -4 °C -14 °C

If exactly one molecule of solute is present in 1.00 L of solution, what is the concentration of the solution? concentration: Consider 1 L of a solution with a concentration of 1 x 10^-25 M. What can be said about the number of solute molecules present? The solution probably does not contain any solute molecules. The solution contains a fraction of a solute molecule. The solution contains more than one solute molecule.

The freezing point of benzene C6H6 is 5.50°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in benzene is testosterone. How many grams of testosterone, C19H2802 (288.4 g/mol), must be dissolved in 200.0 grams of benzene to reduce the freezing point by 0.300°C?

HNO₂ (aq) + NH3(aq) -> NH4+ (aq) + NO₂- (aq) Kc = 1 x 106 Nitrous acid reacts with ammonia according to the balanced chemical equation shown above. If 50. mL of 0.20 M HNO₂ (aq) and 50. mL of 0.20 M NH3(aq) are mixed and allowed to reach equilibrium at 25°C, what is the approximate [NH3] at equilibrium? A 0.00010 M B 0.0010 M C 0.010 M D 0.10 M

A 25.0 mL sample of NaOH requires 42.49 mL of 0.219 M H₂SO4 to reach neutralization. What is the molar concentration of the NaOH solution? H₂SO4(aq) + 2NaOH(aq) --> Na₂SO4(aq) + 2H₂O(l) 0.186 M 0.142 M 0.744 M 0.372 M none of these

Ba(IO3)2(s) -> Ba²+(aq) + 2IO3-(aq) Ksp = 4×10-⁹ According to the information about the dissolution of Ba(IO3)₂(s) shown above, the correct value of S, the molar solubility of Ba(IO3)₂(s), can be calculated using with of the following mathematical relationships? A 1/2S = 4 x 10^-9 M B 2S= 4 x 10^-9 M C S² = 4 x 10^-9M D 4S³ 4x 10^-9 M

A chemist dissolves 577. mg of pure perchloric acid in enough water to make up 110. mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.

A chemist prepares a solution of silver perchlorate (AgClO4) by measuring out 190. g of silver perchlorate into a 100. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's silver perchlorate solution. Be sure your answer has the correct number of significant digits.

Given a concentration of a solution, determine the amount of solute. Percent weight to volume is the number of grams of solute in 100 mL of the solution. A 5.40% (w/v) of aqueous glucose has g of glucose in 150.0 mL of solution.

Given 0.01 M solutions of each of the following acids, which solution would have the lowest pH? Phenol (HC6H50), pka = 9.89 Nitrous acid (HNO2), pKa = 3.34 Acetic acid (HC2H302), pKa = 4.74 Hydrofluoric acid (HF), pKa = 3.46 Formic acid (HCHO2), pKa = 3.74

Calculate the final molarity of H₂O₂ if 5.7 mL of a 3.0% w/w H₂O₂ solution, which has a density of 1.0 g/mL, is added to 5.7 mL of a starch-iodide solution. final [H₂O₂] = M Calculate the final molarity of H₂O₂ if 1.6 mL of the 3.0% w/w H₂O₂ solution is diluted with 3.4 mL water, then added to 5.0 mL of a starch-iodide solution. final [H₂O₂]= M

0.85 g of an organic compound is subjected to Kjeldahl's method for the estimation of nitrogen present. The ammonia evolved, neutralized 12.75 mL of 1 M H₂SO4. The percentage of nitrogen in the compound is

Students added 5.00 mL of 0.200 M CuSO4 solution to a 50-mL volumetric flask, added 10 mL of deionized water and sufficient ammonia solution, and filled the flask to the mark with deionized water. What is the concentration of the resulting solution (in mol/L)?

important values if needed for this question. A mixture of xenon and argon gases, at a total pressure of 702 mm Hg, contains 22.0 grams of xenon and 6.95 grams of argon. What is the partial pressure of each gas in the mixture?

What is the molality of ions in a 0.341 m solution of Li3PO4 assuming the compound dissociates completely?

What is the Molarity of a solution containing 200 grams of NaOH in a 2.5 Liter Solution ? 5 Molarity 2.5 Molarity 5 Molarity 2 Molarity

The Henry's law constant at 25 °C for CO₂ in water is 0.035 M/atm. What is the solubility of CO2, in molarity units, in 1.0 L of water when the partial pressure of CO₂ is 2.3 atm?