Solutions Questions and Answers

The formula for tetraphosphorus decaoxide is P4O10. a. How many grams of phosphorus are present in 4.98 moles of tetraphosphorus decaoxide? grams b. How many moles of oxygen are present in 1.65 grams of tetraphosphorus decaoxide? moles

A chemist prepares a solution of barium chloride (BaCl₂) by measuring out 12. g of barium chloride into a 50. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's barium chloride solution. Round your answer to 2 significant digits.

According to the following reaction, how many grams of water will be formed upon the complete reaction of 29.8 grams of oxygen gas with excess hydrochloric acid? 4HC1 (aq) + O₂(g) 2H₂O (1)+2C1₂ (g)

An aqueous solution has a pH of 5. (1) What is the pOH of this solution? (2) What is the hydroxide ion concentration in this solution? (3) What is the hydronium ion concentration in this solution?

How many moles of HCI are present in 0.70 L of a 0.33 M HCl solution? A 0.23 mol B 0.47 mol C 0.28 mol D) 0.38 mol

Dilution: M₂V₁ = M₂V₂ What volume is needed of 8.00M HCI to make 319mL of 6.80M HCI solution? A) 215 mL B) 302 mL C) 375 mL D) 271 mL

Select the correct answer. The pH scale measures the acidity of a liquid as a function of its hydrogen ion (H+) concentration. pH = -log [H+1] A chemist needs to prepare a solution with a pH of 3. What H+ concentration should the solution have? A 1,000 B. 100 C. 0.01 D. 0.001

A student weighs out a 10.6 g sample of Mn(CH, COO), transfers it to a 250. mL. volumetric flask, adds enough water to dissolve it and then adds water to the 250, ml. tick mark. What is the molarity of manganese(II) acetate in the resulting solution?

Aqueous sulfuric acid (H₂SO₂) will react with solid sodium hydroxide (NaOH) to produce aqueous sodium sulfate (Na₂SO,) and liquid water (H₂O). Suppose 7.85 g of sulfuric acid is mixed with 11. g of sodium hydroxide. Calculate the minimum mass of sulfuric acid that could be left over by the chemical reaction. Round your answer to 2 significant digits.

Determine the molar heat of solution, (ΔHsolution), when 4.08 g of KOH(s) is added to 200.0 mL of water in an insulated container. The temperature increases by 6.81°C. (Assume that the solution has the same physical constants as water)

A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 177. mg of oxalic acid (H₂C₂O₂), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 148.8 ml. of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Round your answer to 3 significant digits.

A chemist makes 540. mL of aluminum sulfate (AL₂(SO4)3) working solution by adding distilled water to 200. mL of a 53.1 mM stock solution of aluminum sulfate in water. Calculate the concentration of the chemist's working solution. Be sure your answer has the correct number of significant digits.

A chemist must prepare 850. mL of 26.0 µM aqueous zinc oxalate (ZnC₂04) working solution. He'll do this by pouring out some 0.000133 M aqueous zinc oxalate stock solution into a graduated cylinder and diluting it with distilled water. Calculate the volume in mL of the zinc oxalate stock solution that the chemist should pour out. Be sure your answer has the correct number of significant digits.

How many milliliters of an aqueous solution of 0.217 M cobalt(II) bromide is needed to obtain 9.18 grams of the salt?

Ammonia (NH3) chemically reacts with oxygen gas (0₂) to produce nitric oxide (NO) and water (H₂O). What mass of oxygen gas is consumed by the reaction of 7.03 g of ammonia? Round your answer to 3 significant digits.

A balloon is filled with 268 L of air at a pressure of 2.9 atm. If the volume of the balloon is halved, what will be the new pressure? What law is used to solve this problem? What is the answer?

You are given a 1.50-g mixture of sodium nitrate and sodium chloride. You dissolve this mixture into 100 mL of water and then add an excess of 0.500 M silver nitrate solution. You produce a white solid, which you then collect, dry, and measure. The white solid has a mass of 0.650 g. a. If you had an extremely magnified view of the solution (to the atomic-molecular level), list the species you would see (include charges, if any). (Enter multiple answers as a comma-separated list.) b. Write the balanced net ionic equation for the reaction that produces the solid. Include phases and charges. (Use the lowest possible coefficients. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank.) c. Calculate the percentage of sodium chloride in the original unknown mixture. % NaCl

Which statement accurately depicts the mass and volume of a gas according to the kinetic molecular theory? Gases have a defined volume and a defined mass. Gases have a defined volume but no defined mass. Gases have no defined volume and no defined mass. Gases have no defined volume but a defined mass.

Ammonium perchlorate (NH4 CIO4) is the solid rocket fuel used by the U.S. Space Shuttle. It reacts with itself to produce nitrogen gas (N₂), chlorine gas (Cl₂) oxygen gas (O.). water (H₂O), and a great deal of energy. What mass of nitrogen gas is produced by the reaction of 5.79 g of ammonium perchlorate? Round your answer to 3 significant digits.

2Na(s) + 2H₂O(n)= 2NaOH(aq)+H₂ If a teacher uses a 0.350 gram sample of sodium metal for a demonstration with excess water, how many liters of hydrogen gas would be produced at STP? 0.171 L of H₂ 0.682 L of H₂ 0.341 L of H₂ 0.718 L of H₂

An unknown molecular compound has molar mass of 58.08 g/mole. If 9.59 x 1025 molecules of this unknown compound occupies a volume of 2.33 mL, what is the density of this compound in g/mL? Answer in scientific notation with correct significant figures and enter "g/mL" for the unit.

Ammonium phosphate ((NH₂),PO₂) ¹ PO is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid (H₂PO₂) with ammonia (NH3)- What mass of ammonium phosphate is produced by the reaction of 5.7 g of ammonia? Round your answer to 2 significant digits.

Which of the following statements shows the correct relationship between temperature and the solubility of a gas in a liquid? Dissolved oxygen in a pond decreases when the water temperature increases. Dissolved oxygen in a pond decreases when the water temperature decreases. More sodium chloride can be dissolved in cold water than in hot water. Carbon dioxide escapes from solution when you open a soda can.

Potassium hydrogen phthalate, KHC8H4O4, is used to standardize solutions of bases. The acidic anion reacts with bases according to this net ionic equation: HC8H404 (aq) + OH-(aq) - - H₂O(l) + C8H404²-(aq) If a 0.9104 g sample of potassium acid phthalate requires 26.87 mL NaOH to react, what is the molarity of the NaOH? 0.0339 M 0.166 M 0.847 M 0.000166 M

A solution is: a mixture of two or more substances. It is heterogeneous at the molecular level. a mixture of two or more substances. It is homogeneous at the molecular level. a mixture of two or more substances, one of which is water. a mixture of two or more substances of the same state (e.g., liquid + liquid).

You measure water in two containers: a 10-mL graduated cylinder with marks at every mL, and a 1-mL pipet marked at every 0.1 mL. If you have some water in each of the containers and add them together, to what decimal place could you report the total volume of water? 0.1 mL 10 mL 0.01 mL 1 mL None of these choices are correct.

Convert 0.4966 m to mm. 496.6 mm 4.966×10-4 m 4.966×10-³ mm 0.04966 mm none of these mm

3. (1 point) Convert 52.3 milliliters to liters. Cross out all the units that cancel out. Metric prefixes are listed in Table 2. Write your answer in a standard format and using scientific notation. 52.3 mL X L/mL= L= (standard format) (scientific notation) L

Comparing potassium nitrate (KNO₃) and sodium chloride (NaCl), which chemical's solubility (in water) is most affected by change in temperature? (Use your notes from your GIZMO worksheet.) a. potassium nitrate b. sodium chloride c. same variation d. impossible to tell

Hydrochloric acid is usually purchased in a concentrated form that is 37.0% HCl by mass and has a density of 1.20 g/mL. How much concentrated solution would it take to prepare 3.05 L of 0.505 M HCl upon dilution with water?

Pineapple juice contains 3.16 x 10‾⁵ M [H3O⁺]. What is the [OH‾] of pineapple juice and is it acidic or basic? Kw = [H₃O⁺][OH‾]; pH = -log[H₃O⁺]; [H₃O⁺] =10‾pH (A) 3.16 x 10‾¹⁰ M; basic (B) 3.16 x 10‾⁹ M; acidic (C) 3.16 x 10‾¹⁰ M; acidic (D) 3.16 x 10‾¹¹ M; acidic (E) 3.16 x 10‾⁹ M; basic

A person forms 8.38mol of C4H10 according to the reaction below. How much energy, in kilojoules, was released? (Use a negative number if energy is released and a positive number if energy is added.)(Round to 2 Decimal Places) 4C (s) + 5H₂ (g) →C4H10 (g) △H° =-125.6 kJ/mol

Calculate the molarity of the following solutions. (a) 76.5 g of HCl in 2.50 L, of a HCl solution (b) 21.0 g of NaOH in 400 mL, of a NaOH solution

A Choose the correct definition for an unsaturated solution in terms of Q and Kc A)If the concentration of the solution-phase solute is smaller than the equilibrium concentration, then Q < Kc, and the solution is unsaturated. B)If the concentration of the solution-phase solute is the same as the equilibrium concentration, then Q = Kc, and the solution is unsaturated. C)If the concentration of the solution-phase solute is greater than the equilibrium concentration, then Q > Kc, and the solution is unsaturated. D)If the concentration of the solution-phase solute is greater than the equilibrium concentration, then Q = Kc, and the solution is unsaturated.

An aqueous solution containing 18.1 g of an unknown molecular (nonelectrolyte) compound in 106.0 g of water was found to have a freezing point of -1.5 °C. Calculate the molar mass of the unknown compound. (Use Kf = 1.86 °C/m). Express your answer using two significant figures.

In general, how does the water solubility of most ionic compounds change as the temperature is increased? solubility decreases solubility increases solubility remains constant solubility depends on the type of ionic compounds (for some it increases and for some it decreases)

Titration of Acetic Acid in Vinegar a) Explain the following terms: titration, titrant, analyte, equivalence point (or stoichiometric point, or endpoint). b) Explain how a pH indicator such as phenolphthalein works. c) Calculate the concentration (molarity or mass percent) of the analyte from experimental data. d) Explain how experimental errors in titration affect results. e) Calculate percent error.

A solution is prepared by dissolving 13.10 g of ordinary sugar (sucrose, C₁₂H₂₂O₁₁, 342.3 g/mol) in 40.80 g of water. Calculate the boiling point of the solution. Sucrose is a nonvolatile nonelectrolyte. Solvent Tb(°C) Kb(°C kg/mol) Tt(°C) Kt(°C kg/mol) Benzene, C₆H₆ 80.1 2.53 5.5 5.10 Camphor, C₁₀H₁₆O 204 5.95 176 37.7 Cyclohexane, C₆H₁₂ 80.88 2.79 6.50 20.2 Nitrobenzene, C₆H₅NO₂ 210.8 5.24 5.7 8.1 Water, H₂O 100.0 0.512 0.00 1.86

A chemist dissolves 780. mg of pure hydrochloric acid in enough water to make up 400. mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.

Hydrogen gas has a Henry's law constant of 1.07x10‾⁶ M/mmHg at 30.0°C when dissolving in water. If the total pressure of gas (H₂ gas plus water vapor) over water is 1.00 atm, what is the concentration of H₂ in the water in grams per milliliter? Pressure of the water vapor at 30.0 °C = 31.8 mmHg.

3b. Another company claims that their D-size cylinders hold 425 L of the gas (obviously their cylinders have a higher gas pressure inside when full). Convert this volume of oxygen to mL and to gallons. Write both numbers in a standard format and in scientific notation. 425 L= mL≈ gal

You are given a substance that is equally soluble in water and hexane (two immiscible solvents). a) What is KD? b) If you start with 10 g of the substance dissolved in 100 mL of water and are given 100 mL of hexane to extract with, algebraically show that it is better to do two smaller extractions using 50 mL of hexane for each extraction than it is to do one extraction using 100 mL of hexane.

You have a solution that contains 4.0 g of oxalic acid dissolved in 100 mL of water. This solution is placed in a separatory funnel, and then 100 mL of diethyl ether is added to the separatory funnel and an extraction is performed. (Diethyl ether and water are immiscible solvents.) Use the following constants to calculate how much oxalic acid is in each solvent after the extraction. Solubility of oxalic acid in water = 9.5 g / 100 mL Solubility of oxalic acid in ether = 16.9 g / 100 mL

A 20.0 mL sample of H₂SO4 was titrated with 22.87 mL of a 1.58 M KOH solution to reach the equivalence point. What is the concentration of the unknown H₂SO4 solution? (Hint: set up a balanced chemical equation) A) 0.09034 M B) 0.1807 M C) 0.18067 M D) 9.034 M E) Who cares!

What is true of a solution of 2.0 M NaCl(aq)? It contains 2.0 grams of NaCl per 100 grams of water. It contains 2.0 grams of NaCl per 1 liter of solution. It contains 2.0 moles of NaCl per 100 grams of water. It contains 2.0 moles of NaCl per 1 liter of solution.

Which statement is true for a solution when its concentration of hydroxide ions becomes equal to the concentration of hydronium ions? (5 points) It becomes more acidic. It becomes more alkaline. Its pH becomes equal to 0. Its pH becomes equal to 7.

Which of the following statements is most accurate? When liquid water is heated, the molecules move faster. When liquid water is heated, the molecules collide more often. When liquid water is heated, collisions between molecules are more violent. All of the answers are correct.

Investigate: Use the Gizmo to explore phase changes. Use the Add/remove heat energy slider to control the water temperature. Record your observations in your notes, then answer the questions below: A. At what temperature does water freeze? B. At what temperature does ice melt? C. At what temperature does water boil? This is the freezing point. This is the melting point. This is the boiling point.

Using the following equation: 2 NaOH + H2SO4 → 2 H2O + Na2SO4 How many grams of sodium sulfate will be formed if you start with 200 grams of sodium hydroxide and you have an excess of sulfuric acid?

What does the "3M" in 3M Cu(NO3)2 tell us? * A) It describes the concentration of the solution that was made from solid Cu(NO3)2 and water. B) It suggests that there are 0.75 moles of Cu(NO3)2 in 0.25 liters of the solution. C) It expresses the number of moles of Cu(NO3)2 dissolved in every liter of solution. D) Answers A and C are both correct. E) Answers A, B, and C are all correct.