Qualitative analysis Questions and Answers

Compared to pure water, an equal volume of NaCl salt water solution will have a ... Higher vapor pressure and higher freezing point and higher boiling point. Lower vapor pressure and lower freezing point and higher boiling point. Lower vapor pressure and lower freezing point and lower boiling point. Higher vapor pressure and higher freezing point and lower boiling point.

The density of aluminum is 2.7 g/cm3. What is the mass of a piece of aluminum foil which is 10.0 cm by 5.0 cm by 0.0018 cm thick? 0.090 g 3.3 × 10-² g 0.24 g 1.4 × 10² g 19 g

The element magnesium, Mg, has three common isotopes:24Mg, 25 Mg, and 26Mg. The difference between these three isotopes is the number of neutrons. the number of electrons. the number of protons. the number of protons and electrons. their physical state.

When a non-polar molecules evaporate, which bonds are broken? Covalent bonds are broken between atoms within the non-polar molecules. lonic bonds are broken between neighboring molecules. Dipolar bonds are broken between neighboring molecules. Dispersion forces are broken between neighboring molecules.

By which of the following mechanisms does a catalyst operate? A catalyst increases the concentration of the reactants. A catalyst provides a reaction pathway that has a greater enthalpy. A catalyst provides a reaction pathway that has a lower activation energy. A catalyst increases the energy of the transitions state. A catalyst serves as a reactant and is consumed.

A balloon has a volume of 8000 mL at 77.5 °F and 1.00 atmosphere of pressure. What is the balloon's new volume if pressure is decreased to 380 torr at -40.0 °C (1 atm = 760 torr). Original temperature in K = 332.9 Final temperature in K = 313.2 Final pressure in atm = 0.50 Final volume of the balloon in L = 150.5 O Original temperature in K = 355.1 Final temperature in K = 313.2 Final pressure in atm = 0.54 Final volume of the balloon in L = 13.0 O Original temperature in K = 298.4 Final temperature in K = 233.2 Final pressure in atm = 0.54 Final volume of the balloon in L = 11.5 Original temperature in K = 298.4 Final temperature in K = 233.2 Final pressure in atm = 0.50 of the balloon in 1 = 434.1

Given the following reaction: CH3COOH + H₂O <==> CH3COO- + H3O+ How would Adding CH3COO and removing H₂O shift the reaction?. This would shift the equilibrium to the right and make the solution more acidic. This would shift the equilibrium to the left and make the solution more acidic. This would shift the equilibrium to the left and make the solution more alkaline. This would shift the equilibrium to the right and make the solution more alkaline.

There are two stable isotopes of boron: boron-10 and boron-11. The atomic weight of boron shown on the Periodic Table is 10.81 amu. Which statement below is correct? boron-10 is the more abundant isotope boron-11 is the less abundant isotope the "average" boron atom has a mass of 10.81 amu the two isotopes are likely to have an equal natural abundance the "average" boron atom has a mass of 10.81 grams

The cleaning action of soaps and detergents is attributable to... their ability to evaporate quickly. their acidic character. their ability to form micelles. their short hydrocarbon tail.

The accepted value of the melting point of pure flurbiprofen is 390 K. Trying to verify that value, you obtain 389 K, 391 K, 386 K, and 394 K in four separate trials. Your partner finds 394 K, 394 392 K. Calculate the average value and percent error for your data and your partner's data. Your average value= Your partner's average value= Your percent error = Your partner's percent error =

On a topographic map, contour lines that are closer together indicate a forest a steeper slope a mountain top roads

Which of the following statements is true? X. CH4 has a higher boiling point than CCl4 Y. trans-1,2-dichloroethene has a lower boiling point than cis-1,2-dichloroethene Z. H₂C-O has a higher boiling point than ethylene, C₂H6. only Z only Y X and Y All of them only X Y and Z X and Z None of them

A flask containing neon gas is connected to an open-ended mercury manometer. The open end is exposed to the atmosphere, where the barometric pressure is 686. torr. The mercury level in the open arm is 7.8 cm above that in the arm connected to the flask of neon. What is the neon pressure, in torr? Provide your answer in decimal notation rounded to the appropriate number of significant figures. Answer: Enter Value torr

Argon has normal boiling and freezing points of 87.3 K and 83.8 K, respectively. The triple point of argon occurs at 83.8 K at 0.68 atm. What physical change can be observed - if any - when the temperature of an argon sample is increased from 85 K to 90 K at a constant pressure of 0.46 atm? no physical change occurs - the sample is gas and stays gas solid to liquid liquid to gas no physical change occurs - the sample is liquid and stays liquid solid to gas

How many moles of solid Ba(NO3)2 should be added to 300. mL of 0.20 M Fe(NO3)3 to increase the concentration of NO3- ion to 1.0 M? (Assume that the volume of the solution remains constant) a) 0.060 mol b) 0.12 mol c) 0.24 mol d) 0.41 mol

Alchemist adds 340.0 mL of a 2.5 mol/L potassium iodide (KI) solution to a reaction flask. Calculate the mass in kilograms of potassium iodide the chemist has added to the flask.

A 50.0 mL sample of 0.010 M HCI solution was diluted to 500.0 mL. What is the pOH of the new acid solution? But first answer these questions: 1st) What is the pH of the original 0.010 M HCl solution: [H+]=0.010M 2nd) What is the molar concentration of the new dilute solution: 3rd) What is the pH of the new dilute acid solution: 4th) What is pOH of the new dilute acid solution. (A) 1st) pH of original = 2.0 2nd) Concentration of dilution solution = 0.001 M 3rd) pH of dilution solution = 11.0 4th) pOH of dilution solution = 3.0 (B) 1st) pH of original = 1.0 2nd) Concentration of dilution solution = 0.1 M 3rd) pH of dilution solution = 1.0 4th) pOH of dilution solution = 13.0 (C) 1st) pH of original = 1.0 2nd) Concentration of dilution solution = 0.001 M 3rd) pH of dilution solution = 3.0 4th) pOH of dilution solution 11.0 B

What volume of a 0.160 M hydroiodic acid solution is required to neutralize 26.9 mL of a 0.101 M sodium hydroxide solution?

What would be the pH of a solution if 0.0010 moles of KOH was mixed with 0.0015 moles of HNO3? Assume volume is 1 L Assume volume is 1.0 L. HNO3 is more than KOH a how much extra HNO3 do we have? knowing this will allow you to get [H+] which will allow you to calculate the pH. a. Solution pH = 2.8 b. Solution pH = 3.3 c. Solution pH = 3.0 d. Solution pH = 11.0

What is true of an alkaline solution? An alkaline solution has more hydrondium ions than hydroxide ions. An alkaline solution contains more H3O+ ions than OH ions. An alkaline solution has the same number of hydroxide ions as hydrondium ions. An alkaline solution has more hydroxide ions than hydronium ions.

A chemist must prepare 800.0 mL of hydrobromic acid solution with a pH of 0.60 at 25 °C. He will do this in three steps: • Fill a 800.0 mL volumetric flask about halfway with distilled water. • Measure out a small volume of concentrated (6.0 M) stock hydrobromic acid solution and add it to the flask. • Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrobromic acid that the chemist must measure out in the second step.

A chemist must prepare 450.0 mL of hydrobromic acid solution with a pH of 1.60 at 25 °C. He will do this in three steps: • Fill a 450.0 mL volumetric flask about halfway with distilled water. • Measure out a small volume of concentrated (6.0M) stock hydrobromic acid solution and add it to the flask. • Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrobromic acid that the chemist must measure out in the second step.

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(II) carbonate, in concentrated sulfuric acid. The sulfuric acid reacts with the copper(II) carbonate to produce a blue solution of copper(II) sulfate. Scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: Fe(s) + CuSO4(aq) Cu(s) + FeSO4(aq) Suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. He adds powdered iron to a 100. mL copper(II) sulfate sample from the plant until no more copper will precipitate. He then washes, dries, and weighs the precipitate, and finds that it has a mass of 135. mg. Calculate the original concentration of copper(II) sulfate in the sample.

An analytical chemist weighs out 0.024 g of an unknown monoprotic acid into a 250 mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.1700 M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 1.5 mL of NaOH solution. Calculate the molar mass of the unknown acid.

The decomposition of ethane to methyl radicals is a first-order reaction with a rate constant of 5.36 x 104 s-¹. Calculate the half-life of the reaction in minutes. How long would it take for the concentration of ethane to decrease to 50% of its initial value? How long will it take to decrease to 25%, 12.5 %?

Consider the following reaction: HSO4 (aq) + HCl(aq) → SO42-(aq) + H₂CI+ (aq) Apply the Brønsted-Lowry definition of acids and bases the classify each species correctly: HSO4 = HCI = SO4²- = H₂CI+=

The water-insoluble component C collected is collected by filtration. The solid is dried on an evaporating dish weighing 71.83 g. The combined weight of the dish and dried solid is 72.30 g. What is the weight of Component C? Calculate the weight percent of component C in the original mixture.

The meta-cresol purple pt indicator has two pH ranges 12-28 (red to yellow) 7.4-9.0 (yellow to purple) After adding meta-cresol purple indicator to a solution, it turned red. What is the pH range of the solution? A. pH below 1.2 B. pH = 1.2 - 2.8 C. pH = 2.8 - 7.4 D. pH = 7.4 - 9.0 E. pH above 9.0

In a titration experiment,16.50 mL of 0.100 M HCl was needed to titrate 0.153g of an unknown amine to a neutral pH endpoint. What is the molecular weight of the amine? Assume the compound only contains one nitrogen atom and there are no other reactive groups present.