Question: What is a standard solution? Describe the

> Calcium carbonate, CaCO3, can be obtained in a very pure state. Standard solutions of calcium ion are usually prepared by dissolving calcium carbonate in acid. What mass of CaCO3 should be taken to prepare 500. mL of 0.0200 M calcium ion solution?

> The “Chemistry in Focus” segment Garden-Variety Acid– Base Indicators discusses acid–base indicators found in nature. What colors are exhibited by red cabbage juice under acid conditions? Under basic conditions?

> If 10. g of AgNO3 is available, what volume of 0.25 M AgNO3 solution can be prepared?

> How do the components of a conjugate acid–base pair differ from one another? Give an example of a conjugate acid–base pair to illustrate your answer.

> How many moles of the indicated solute does each of the following solutions contain? a. 1.5 L of 3.0 M H2SO4 solution b. 35 mL of 5.4 M NaCl solution c. 5.2 L of 18 M H2SO4 solution d. 0.050 L of 1.1 * 10-3 M NaF solution

> Water is the most common amphoteric substance, which means that, depending on the circumstances, water can behave either as an acid or as a base. Using HF as an example of an acid and NH3 as an example of a base, write equations for these substances reac

> For each of the following solutions, the mass of solute is given, followed by the total volume of the solution prepared. Calculate the molarity of each solution. a. 3.51 g NaCl; 25 mL b. 3.51 g NaCl; 50. mL c. 3.51 g NaCl; 75 mL d. 3.51 g NaCl; 1.00

> Concentrated hydrochloric acid is made by pumping hydrogen chloride gas into distilled water. If concentrated HCl contains 439 g of HCl per liter, what is the molarity?

> Complete the table for each of the following solutions: [H*] pH pOH [OH=] 0.0070 М HNO, 3.0 М КОН

> Choose pairs in which the species listed first is the conjugate base of the species listed second. a. S2-, HS- b. H+, OH- c. HBr, Br- d. NO2-, HNO2

> You add 40.0 mL of water to 60.0 mL of a 2.00 M calcium chloride solution. How many moles of calcium chloride are in the new solution?

> How many moles of each ion are present in 11.7 mL of 0.102 M Na3PO4 solution?

> A solution contains 7.5% by mass NaCl and 2.5% by mass KBr. What mass of each solute is contained in 125 g of the solution?

> What mass of KNO3 is required to prepare 125 g of 1.5% KNO3 solution?

> How many grams of Na2CO3 are contained in 500. g of a 5.5% by mass Na2CO3 solution?

> A sugar solution is prepared in such a way that it contains 10.% dextrose by mass. What quantity of this solution do we need to obtain 25 g of dextrose?

> A certain grade of steel is made by dissolving 5.0 g of carbon and 1.5 g of nickel per 100. g of molten iron. What is the mass percent of each component in the finished steel?

> Calculate the [OH-] in each of the following solutions, and indicate whether the solution is acidic or basic. a. [H+] = 1.02 * 10-7 M b. [H+] = 9.77 * 10-8 M c. [H+] = 3.41 * 10-3 M d. [H+] = 4.79 * 10-11 M

> What is an oxyacid? Write the formulas of three acids that are oxyacids. Write the formulas of three acids that are not oxyacids.

> Calculate the mass, in grams, of NaCl present in each of the following solutions. a. 11.5 g of 6.25% NaCl solution b. 6.25 g of 11.5% NaCl solution c. 54.3 g of 0.91% NaCl solution d. 452 g of 12.3% NaCl solution

> A solution is 0.1% by mass calcium chloride. Therefore, 100. g of the solution contains g of calcium chloride.

> Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pH values. a. pH = 8.34 b. pH = 5.90 c. pH = 2.65 d. pH = 12.6

> An experiment calls for 1.00 g of silver nitrate, but all that is available in the laboratory is a 0.50% solution of AgNO3. Assuming the density of the silver nitrate solution to be very nearly that of water because it is so dilute, determine how many mi

> The concentration of a solution of HCl is 33.1% by mass, and its density was measured to be 1.147 g/mL. How many milliliters of the HCl solution are required to obtain 10.0 g of HCl?

> Calculate the pOH corresponding to each of the pH values listed, and indicate whether each solution is acidic, basic, or neutral. a. pH = 1.02 b. pH = 13.4 c. pH = 9.03 d. pH = 7.20

> What volume of hydrogen chloride gas at STP is required to prepare 500. mL of 0.100 M HCl solution?

> Aqueous ammonia is typically sold by chemical supply houses as the saturated solution, which has a concentration of 14.5 mol/L. What volume of NH3 at STP is required to prepare 100. mL of concentrated ammonia solution?

> Strictly speaking, the solvent is the component of a solution that is present in the largest amount on a mole basis. For solutions involving water, water is almost always the solvent because there tend to be many more water molecules present than molecul

> Calculate the [OH-] in each of the following solutions, and indicate whether the solution is acidic or basic. a. [H+] = 4.01 * 10-4 M b. [H+] = 7.22 * 10-6 M c. [H+] = 8.05 * 10-7 M d. [H+] = 5.43 * 10-9 M

> Organic acids contain the carboxyl group Using acetic acid, CH3-COOH, and propionic acid, CH3CH2-COOH, write equations showing how the carboxyl group enables these substances to behave as weak acids when dissolved in water. `0-H

> Name four strong acids. For each of these, write the equation showing the acid dissociating in water.

> If 500. g of water is added to 75 g of 25% NaCl solution, what is the percent by mass of NaCl in the diluted solution?

> Write the conjugate base for each of the following. a. H3PO4 b. HCO3- c. HF d. H2SO4

> Write the conjugate acid for each of the following. a. NH3 b. NH2- c. H2O d. OH-

> In each of the following chemical equations, identify the conjugate acid–base pairs. a. CH3NH2 + H2O ⇌ CH3NH3+ + OH- b. CH3COOH + NH3 ⇌ CH3COO- + NH4+ c. HF + NH3 ⇌ F- + NH4+

> Suppose that 27.34 mL of standard 0.1021 M NaOH is required to neutralize 25.00 mL of an unknown H2SO4 solution. Calculate the molarity and the normality of the unknown solution.

> When hydrochloric acid, HCl, is added dropwise to a buffered solution, the component of the buffer consumes the added hydrogen ion.

> When sodium hydroxide, NaOH, is added dropwise to a buffered solution, the component of the buffer consumes the added hydroxide ion.

> Calculate the [H+] in each of the following solutions, and indicate whether the solution is acidic, basic, or neutral. a. [OH-] = 7.86 * 10-4 M b. [OH-] = 5.44 * 10-2 M c. [OH-] = 3.19 * 10-3 M d. [OH-] = 2.51 * 10-9 M

> How many milliliters of 0.50 N NaOH are required to neutralize exactly 15.0 mL of 0.35 N H2SO4?

> A buffered solution is one that resists a change in when either a strong acid or a strong base is added to it.

> A solution of phosphoric acid, H3PO4, is found to contain 35.2 g of H3PO4 per liter of solution. Calculate the molarity and normality of the solution.

> Calculate the normality of each of the following solutions. a. 0.134 M NaOH b. 0.00521 M Ca(OH)2 c. 4.42 M H3PO4

> Calculate the normality of each of the following solutions. a. 0.250 M HCl b. 0.105 M H2SO4 c. 5.3 * 10-2 M H3PO4

> The ion-product constant for water, Kw, has the value at 25 °C.

> For each of the following solutions, calculate the normality. a. 25.2 mL of 0.105 M HCl diluted with water to a total volume of 75.3 mL b. 0.253 M H3PO4 c. 0.00103 M Ca(OH)2

> How many equivalents of hydroxide ion are needed to react with 1.53 equivalents of hydrogen ion? How did you know this when no balanced chemical equation was provided for the reaction?

> An acid such as HCl that strongly conducts an electric current when dissolved in water is said to be a(n) acid.

> A solution that contains 1 equivalent of acid or base per liter is said to be a solution.

> One equivalent of an acid is the amount of the acid required to provide .

> According to the Brønsted–Lowry model, a base is a species that protons.

> According to Arrhenius, bases are species that produce ions in aqueous solution.

> The total acidity in water samples can be determined by neutralization with standard sodium hydroxide solution. What is the total concentration of hydrogen ion, H+, present in a water sample if 100. mL of the sample requires 7.2 mL of 2.5 * 10-3 M NaOH t

> Is it possible for a solution to have [H+] = 0.002 M and [OH-] = 5.2 * 10-6 M at 25 °C? Explain.

> What volume of a 0.500 M NaOH solution would be required to neutralize 40.0 mL of a 0.400 M H2SO4 solution?

> What volume of 0.502 M NaOH solution would be required to neutralize 27.2 mL of 0.491 M HNO3 solution?

> Of the following conditions, which indicate a basic solution? a. pOH = 12.53 b. pH = 3.64 c. pOH < [H1] d. [OH-] > 1.0 * 10-7 M

> Of the following conditions, which indicate an acidic solution? a. pH = 8.95 b. [H+] < 1.0 * 10-7 M c. pOH = 3.46 d. [OH-] = 7.11 * 10-10 M

> Write an equation showing how HCl(g) behaves as an Arrhenius acid when dissolved in water. Write an equation showing how NaOH(s) behaves as an Arrhenius base when dissolved in water.

> What happens to the hydroxide ion concentration in aqueous solutions when we increase the hydrogen ion concentration by adding an acid? What happens to the hydrogen ion concentration in aqueous solutions when we increase the hydroxide ion concentration b

> According to the Brønsted-Lowry model, an acid is a “proton donor” and a base is a “proton acceptor.” Explain.

> Write a chemical equation showing how each of the following species can behave as indicated when dissolved in water. a. O2- as a base b. NH3 as a base c. HSO4- as an acid d. HNO- as an acid

> Generally only the carbonates of the Group 1 elements and the ammonium ion are soluble in water; most other carbonates are insoluble. How many milliliters of 0.125 M sodium carbonate solution would be needed to precipitate the calcium ion from 37.2 mL of

> Write a chemical equation showing how each of the following species can behave as indicated when dissolved in water. a. HSO3- as an acid b. CO32- as a base c. H2PO4- as an acid d. C2H3O2- as a base

> During a summer research internship, you are asked to do lab work and prepare solutions for experiments to be run on samples that will come in from the field. You need to prepare a 0.300 M NaOH solution but only have 6.00 M NaOH on the shelf. What volume

> How much water must be added to 500. mL of 0.200 M HCl to produce a 0.150 M solution? (Assume that the volumes are additive.)

> Suppose 325 mL of 0.150 M NaOH is needed for your experiment. How would you prepare this if all that is available is a 1.01 M NaOH solution?

> How would you prepare 275 mL of 0.350 M NaCl solution using an available 2.00 M solution?

> For convenience, one form of sodium hydroxide that is sold commercially is the saturated solution. This solution is 19.4 M, which is approximately 50% by mass sodium hydroxide. What volume of this solution would be needed to prepare 3.50 L of 3.00 M NaOH

> Many laboratories keep bottles of 3.0 M solutions of the common acids on hand. Given the following molarities of the concentrated acids, determine how many milliliters of each concentrated acid would be required to prepare 225 mL of a 3.0 M solution of t

> A bottle of acid solution is labeled “3 M HNO3.” What are the substances that are actually present in the solution? Are any HNO3 molecules present? Why or why not?

> What is meant by the ion-product constant for water, Kw? What does this constant signify? Write an equation for the chemical reaction from which the constant is derived.

> When 1 mole of gaseous hydrogen chloride is dissolved in enough water to make 1 L of solution, approximately how many HCl molecules remain in the solution? Explain.

> When the volume of a given solution is tripled (by adding water), the new concentration of solute is the original concentration.

> When a concentrated stock solution is diluted to prepare a less concentrated reagent, the number of is the same both before and after the dilution.

> What volume of a 0.300 M CaCl2 solution is needed to prepare 240. mL of a 0.100 M Cl- solution?

> An experiment calls for 125 mL of 0.105 M NaCl solution. What mass of NaCl is required? What mass of NaCl would be required for 1.00 L of the same solution?

> Calculate the hydrogen ion concentration, in moles per liter, for solutions with each of the following pH values. a. pH = 2.75 b. pH = 12.8 c. pH = 4.33 d. pH = 9.61

> Write the conjugate base for each of the following acids. a. HBrO b. HNO2 c. HSO3- d. CH3NH3+

> What mass of solute is present in 225 mL of 0.355 M KBr solution?

> What mass of NaOH pellets is required to prepare 3.5 L of 0.50 M NaOH solution?

> Calculate the pOH value corresponding to each of the pH values listed, and tell whether each solution is acidic or basic. a. pH = 10.75 b. pH = 3.66 c. pH = 1.98 d. pH = 12.47

> Anions containing hydrogen (for example, HCO3- and H2PO42-) show amphoteric behavior when reacting with other acids or bases. Write equations illustrating the amphoterism of these anions.

> Calculate the pH corresponding to each of the pOH values listed, and indicate whether each solution is acidic, basic, or neutral. a. pOH = 4.32 b. pOH = 8.90 c. pOH = 1.81 d. pOH = 13.1

> Write the conjugate base for each of the following acids: a. H2S b. HS2 c. NH3 d. H2SO3

> Write the conjugate acid for each of the following bases. a. ClO- b. Cl- c. ClO3- d. ClO4-

> Standard silver nitrate solutions are used in the analysis of samples containing chloride ion. How many grams of silver nitrate are needed to prepare 250. mL of a 0.100 M AgNO3 solution?

> If 42.5 g of NaOH is dissolved in water and diluted to a final volume of 225 mL, calculate the molarity of the solution.

> An alcoholic iodine solution (“tincture” of iodine) is prepared by dissolving 5.15 g of iodine crystals in enough alcohol to make a volume of 225 mL. Calculate the molarity of iodine in the solution.

> Standard solutions of calcium ion used to test for water hardness are prepared by dissolving pure calcium carbonate, CaCO3, in dilute hydrochloric acid. A 1.745-g sample of CaCO3 is placed in a 250.0-mL volumetric flask and dissolved in HCl. Then the sol

> How many grams of formaldehyde are in 113.1 mL of a 3.0 M aqueous solution of formaldehyde? The formula for formaldehyde is HCHO.

> A laboratory assistant needs to prepare 225 mL of 0.150 M CaCl2 solution. How many grams of calcium chloride will she need?

> For each pair of concentrations, tell which represents the more basic solution. a. [H+] = 2.02 * 10-7 M or [OH-] = 5.05 * 10-5 M b. [H+] = 1.79 * 10-5 M or [OH-] = 4.21 * 10-6 M c. [H+] = 1.25 * 10-12 M or [OH-] = 6.51 * 10-3 M

> Sulfuric acid has a great affinity for water, and for this reason, the most concentrated form of sulfuric acid available is actually a 98.3% solution. The density of concentrated sulfuric acid is 1.84 g/mL. What mass of sulfuric acid is present in 1.00 L

> For each pair of concentrations, tell which represents the more acidic solution. a. [H+] = 1.2 * 10-3 M or [H+] = 4.5 * 10-4 M b. [H+] = 2.6 * 10-6 M or [H+] = 4.3 * 10-8 M c. [H+] = 0.000010 M or [H+] = 0.0000010 M

> For each of the following solutions, the number of moles of solute is given, followed by the total volume of the solution prepared. Calculate the molarity of each solution. a. 0.754 mol KNO3; 225 mL b. 0.0105 mol CaCl2; 10.2 mL c. 3.15 mol NaCl; 5.00

> For each of the following solutions, the number of moles of solute is given, followed by the total volume of the solution prepared. Calculate the molarity of each solution. a. 0.521 mol NaCl; 125 mL b. 0.521 mol NaCl; 250. mL c. 0.521 mol NaCl; 500. m

> To prepare 500. mL of 1.02 M sugar solution, which of the following would you need? a. 500. mL of water and 1.02 mole of sugar b. 1.02 mole of sugar and enough water to make the total volume 500. mL c. 500. g of water and 1.02 mole of sugar d. 0.51 m

> Write the conjugate acid for each of the following bases: a. PO43- b. IO3- c. NO3- d. NH2-

> A solution labeled “0.25 M AlCl3” would contain mole(s) of Al3+ and mole(s) of Cl- in each liter of the solution.