Questions and Answers of General Chemistry

A sample of carbon dioxide gas is placed in a container. The volume of the container is reduced to 1/3 of its original volume while the pressure is observed to double. In this system did the
The atmosphere in a sealed diving bell contained oxygen and helium. If the gas mixture has 0.200 atm of oxygen and a total pressure of 3.00 atm, calculate the mass of helium in 10.0 L of the gas
A 900.0-mL flask contains 1.16 mg O2 and 0.42 mg He at 15°C. Calculate the partial pressures of oxygen and of helium in the flask. What is the total pressure?
Calculate the total pressure (in atm) of a mixture of 0.0300 mol of helium, He, and 0.0400 mol of oxygen, O2, in a 4.00-L flask at 20°C. Assume ideal gas behavior
Nitric acid is produced from nitrogen monoxide, NO, which in turn is prepared from ammonia by the Ostwald process:4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)What volume of oxygen at 35°C and 2.15 atm is
Magnesium burns in air to produce magnesium oxide, MgO, and magnesium nitride, Mg3N2. Magnesium nitride reacts with water to give ammonia.Mg3N2(s) + 6H2O(l) → 3Mg(OH)2(s) + 2NH3(g)What volume of
Calcium carbide reacts with water to produce acetylene gas, C2H2.CaC2(s) + 2H2O(l) → Ca(OH)2(aq) + C2H2(g)Calculate the volume (in liters) of acetylene produced at 26°C and 684 mmHg from 0.075 mol
Butane, C4H10, is an easily liquefied gaseous fuel. Calculate the density of butane gas at 0.857 atm and 22°C. Give the answer in grams per liter.
Calculate the density of hydrogen sulfide gas, H2S, at 49°C and 967 mmHg. Obtain the density in grams per liter.
According to your calculations, a reaction should yield 5.67 g of oxygen, O2. What do you expect the volume to be at 23°C and 0.894 atm?
In an experiment, you fill a heavy-walled 6.00-L flask with methane gas, CH4. If the flask contains 7.13 g of methane at 19°C, what is the gas pressure?
A bacterial culture isolated from sewage produced 51.5 mL of methane, CH4, at 33°C and 752 mmHg. What is the volume of this methane at standard temperature and pressure (0°C, 760 mmHg)?
A vessel containing 39.5 cm3 of helium gas at 25°C and 106 kPa was inverted and placed in cold ethanol. As the gas contracted, ethanol was forced into the vessel to maintain the same pressure of
An experiment called for 4.83 L of sulfur dioxide, SO2, at 0°C and 1.00 atm. What would be the volume of this gas at 29°C and 1.00 atm?
A sample of nitrogen gas at 17°C and 760 mmHg has a volume of 8.06 mL. What is the volume at – 9°C and 1 atm of pressure?
If 456 dm3 of krypton at 101 kPa and 21°C is compressed into a 30.1-dm3 tank at the same temperature, what is the pressure of krypton in the tank?
You fill a balloon with helium gas to a volume of 2.68 L at 23°C and 789 mmHg. Now you release the balloon. What would be the volume of helium if its pressure changed to 499 mmHg but the temperature
Suppose you had a 4.10-L sample of neon gas at 21°C and a pressure of 0.959 atm. What would be the volume of this gas if the pressure were increased to 1.210 atm while the temperature remained
The barometric pressure measured outside an airplane at 9 km (30,000 ft) was 266 torr. Calculate the pressure in kPa.
Consider a sealed glass bottle of helium gas at room temperature. If you immerse the bottle in an ice water bath, how will this immersion affect the pressure of the gas?I. Pressure increaseII.
You are asked to prepare 0.250 L of a solution that is 0.500 M in nitrate ion. Your only source of nitrate ion is a bottle of 1.00 M calcium nitrate. What volume (mL) of the calcium nitrate solution
How many grams of precipitate are formed if 175 mL of a 0.750 M aluminum sulfate solution and 375 mL of a 1.15 M sodium hydroxide solution are mixed together?
Nitric acid can be reacted with zinc according to the following chemical equation.4HNO3(aq) + Zn(s) → Zn(NO3)2(aq) + 2H2O(l) + 2NO2(g)If 3.75 g of Zn is added to 175 mL of 0.500 M HNO3, what mass
What is the molarity of pure water with a density of 1.00 g/mL?
A 25-mL sample of 0.50 M NaOH is combined with a 75-mL sample of 0.50 M NaOH. What is the concentration of the resulting NaOH solution?
Arsenic acid, H3AsO4, is a poisonous acid that has been used in the treatment of wood to prevent insect damage. Arsenic acid has three acidic protons. Say you take a 25.00-mL sample of arsenic acid
An aluminum nitrate solution is labeled 0.256 M. If 31.6 mL of this solution is diluted to a total of 65.1 mL, calculate the molarity of nitrate ion in the resulting solution.
If 45.1 mL of a solution containing 8.30 g of silver nitrate is added to 31.3 mL of 0.511 M sodium carbonate solution, calculate the molarity of silver ion in the resulting solution. (Assume volumes
An antacid tablet contains sodium hydrogen carbonate, NaHCO3, and inert ingredients. A 0.465-g sample of powdered tablet was mixed with 53.3 mL of 0.190 MHCl (hydrochloric acid). The mixture was
An antacid tablet has calcium carbonate as the active ingredient; other ingredients include a starch binder. You dissolve the tablet in hydrochloric acid and filter off insoluble material. You add
An aqueous solution contains 3.75% NH3 (ammonia) by mass. The density of the aqueous ammonia is 0.979 g/mL. What is the molarity of NH3 in the solution?
An aqueous solution contains 3.75 g of iron(III) sulfate, Fe2(SO4)3, per liter. What is the molarity of Fe2(SO4)3? When the compound dissolves in water, the Fe3+ ions and SO42- ions in the crystal go
An aqueous solution contains 5.00 g of calcium chloride, CaCl-, per liter. What is the molarity of CaCl-? When calcium chloride dissolves in water, the calcium ions, Ca2+, and chloride ions, Cl-, in
Classify each of the following reactions as a combination reaction, decomposition reaction, displacement reaction, or combustion reaction.a. When solid calcium oxide, CaO, is exposed to gaseous
Classify each of the following reactions as a combination reaction, decomposition reaction, displacement reaction, or combustion reaction.a. When they are heated, ammonium dichromate crystals,
Nickel(II) sulfate solution reacts with sodium hydroxide solution to produce a precipitate of nickel(II) hydroxide and a solution of sodium sulfate. Write the molecular equation for this reaction.
A 3.75-g sample of iron ore is transformed to a solution of iron(II) sulfate, FeSO4, and this solution is titrated with 0.150 M K2Cr2O7 (potassium dichromate). If it requires 43.7 mL of potassium
How many milliliters of 0.250 M KMnO4 are needed to react with 3.55 g of iron(II) sulfate, FeSO4? The reaction is as follows: 10FESO,(aq) + 2KMNO,(aq) + 8H,SO,(aq) → 5Fe,(SO4);(aq) + 2MNSO,(aq) +
How many milliliters of 0.250 M H2SO4 (sulfuric acid) are required to react with 8.20 g of sodium hydrogen carbonate, NaHCO3, according to the following equation?H2SO4(aq) + 2NaHCO3(aq) h Na2SO4(aq)
A flask contains 49.8 mL of 0.150 M Ca(OH)2 (calcium hydroxide). How many milliliters of 0.500 M Na2CO3 (sodium carbonate) are required to react completely with the calcium hydroxide in the
What volume of 0.230 M HNO3 (nitric acid) reacts with 49.0 mL of 0.330 M Na2CO3 (sodium carbonate) in the following reaction?2HNO3(aq) + Na2CO3(aq) → 2NaNO3(aq) + H2O(l) + CO2(g)
A 8.50 g sample of KCl is dissolved in 66.0 mL of water. The resulting solution is then added to 72.0 mL of a 0.280 M CaCl2(aq) solution. Assuming that the volumes are additive, calculate the
A chemist wants to prepare 0.75 M HCl. Commercial hydrochloric acid is 12.4 M. How many milliliters of the commercial acid does the chemist require to make up 1.50 L of the dilute acid?
Describe how you would prepare 2.50 × 102 mL of 0.50 M Na2SO4. What mass (in grams) of sodium sulfate, Na2SO4, is needed?
How many grams of sodium dichromate, Na2Cr2O7, should be added to a 100.0-mL volumetric flask to prepare 0.033 M Na2Cr2O7 when the flask is filled to the mark with water?
What is the volume (in milliliters) of 0.100 M H2SO4 (sulfuric acid) containing 0.949 g H2SO4?
How many milliliters of 0.126 M HClO4 (perchloric acid) are required to give 0.150 mol HClO4?
A sample of oxalic acid, H2C2O4, weighing 1.200 g is placed in a 100.0-mL volumetric flask, which is then filled to the mark with water. What is the molarity of the solution?
A 50.0-mL volume of AgNO3 solution contains 0.0345 mol AgNO3 (silver nitrate). What is the molarity of the solution?
A sample of 0.0606 mol of iron(III) chloride, FeCl3, was dissolved in water to give 35.4 mL of solution. What is the molarity of the solution?
Obtain the oxidation number for the element noted in each of the following.a. N in NH2-b. I in IO3-c. H in H2d. Cl in HClO4
Obtain the oxidation number for the element noted in each of the following.a. Sn in SnO2b. Ta in Ta2O3c. Br in KBrO4d. Os in K2OsO4
For each of the following, write the molecular equation, including phase labels. Then write the net ionic equation. Note that the salts formed in these reactions are soluble.a. The neutralization of
For each of the following, write the molecular equation, including phase labels. Then write the net ionic equation. Note that the salts formed in these reactions are soluble.a. The neutralization of
Classify each of the following as a strong or weak acid or base.a. NH3b. HCNOc. Mg(OH)2d. HClO3
For each of the following, write molecular and net ionic equations for any precipitation reaction that occurs. If no reaction occurs, indicate this.a. Solutions of barium nitrate and lithium sulfate
Write the molecular equation and the net ionic equation for each of the following aqueous reactions. If no reaction occurs, write NR after the arrow.a. AgNO3 + NaI →b. Ba(NO3)2 + K2SO4 →c. NH4NO3
Lithium carbonate solution reacts with aqueous hydrobromic acid to give a solution of lithium bromide, carbon dioxide gas, and water. Write the molecular equation and the net ionic equation for the
Using solubility rules, predict the solubility in water of the following ionic compounds.a. Al(OH)3b. Ca3N2c. NH4Cld. KOH
Try and answer the following questions without using a calculator.a. A solution is made by mixing 1.0 L of 0.5 M NaCl and 0.5 L of 1.0 M CaCl2. Which ion is at the highest concentration in the
You come across a beaker that contains water, aqueous ammonium acetate, and a precipitate of calcium phosphate.a. Write the balanced molecular equation for a reaction between two solutions containing
You need to perform gravimetric analysis of a water sample in order to determine the amount of Ag+ present.a. List three aqueous solutions that would be suitable for mixing with the sample to perform
Complete and balance the two chemical equations.HClO4(aq) + H2O(l) →HBr(aq) + H2O(l) →Which of the following statements is true regarding the solutions formed after the two chemical reactions
Which of the following would you expect to be strong electrolytes when placed in water?NH4Cl MgBr2 H2O HCl Ca3(PO4)2
Calculate the rms speed of Br2 molecules at 23°C and 1.00 atm. What is the rms speed of Br2 at 23°C and 2.00 atm?
At what temperature does the rms speed of O2 molecules equal 475. m/s?
If it takes 11.2 hours for 1.00 L of nitrogen, N2, to effuse through the pores in a balloon, how long would it take for 1.00 L of helium, He, to effuse under the same conditions?
A glass tumbler containing 243 cm3 of air at 1.00 × 102 kPa (the barometric pressure) and 20°C is turned upside down and immersed in a body of water to a depth of 25.5 m. The air in the glass is
The density of air at 20°C and 1.00 atm is 1.205 g/L. If this air were compressed at the same temperature to equal the pressure at 50.0 m below sea level, what would be its density? Assume the
A volume of air is taken from the earth’s surface, at 19°C and 1.00 atm, to the stratosphere, where the temperature is – 21°C and the pressure is 1.00 × 10–3 atm. By what factor is the
A radioactive metal atom decays (goes to another kind of atom) by emitting an alpha particle (He2+ ion). The alpha particles are collected as helium gas. A sample of helium with a volume of 9.050 mL
Liquid oxygen was first prepared by heating potassium chlorate, KClO3, in a closed vessel to obtain oxygen at high pressure. The oxygen was cooled until it liquefied.2KClO3(s) → 2KCl(s) + 3O2(g)If
Raoul Pictet, the Swiss physicist who first liquefied oxygen, attempted to liquefy hydrogen. He heated potassium formate, KCHO2, with KOH in a closed 2.50-Lvessel.KCHO2(s) + KOH(s) → K2CO3(s) +
A 48.90-mL sample of a 0.2040 M acid reacts with an excess of Na2CO3 to form 125.0 mL CO2 at 722 mmHg and 17°C. If the acid is either HCl or H2SO4, which is it?
If the rms speed of NH3 molecules is found to be 0.600 km/s, what is the temperature (in degrees Celsius)?
A given mass of gas occupies a volume of 435 mL at 28°C and 740 mmHg. What will be the new volume at STP?
A 275-mL sample of CO gas is collected over water at 31oC and 755 mmHg. If the temperature of the gas collection apparatus rises to 39oC, what is the new volume of the sample? Assume that the
If you have a 150-L cylinder filled with chlorine gas to a density of 2.8 g/L, how many moles of chlorine would you need to add to the cylinder? If you were to double the temperature of the cylinder,
Hypothetical elements A2 and B2 react according to the following equation, forming the compound AB.A2(aq) + B2(aq) → 2AB(aq); ∆H° = +271 kJ/molIf solutions A2(aq) and B2(aq), starting at the
Consider the following specific heats of metals.Metal .......................Specific Heatcopper...................... 0.385 J/(g∙°C)magnesium ...............1.02 J/(g∙°C)mercury
Shown below is a diagram depicting the enthalpy change of a chemical reaction run at constant pressure.a. Is the reaction exothermic or endothermic?b. What is the sign of ∆H?c. What is the sign of
Hydrogen sulfide, H2S, is produced during decomposition of organic matter. When 0.5000 mol H2S burns to produce SO2(g) and H2O(l), –281.0 kJ of heat is released. What is this heat in kilocalories?
A car whose mass is 5.30 × 103 lb is traveling at a speed of 57 miles per hour. What is the kinetic energy of the car in joules? in calories?
The decomposition of ozone, O3, to oxygen, O2, is an exothermic reaction. What is the sign of q? If you were to touch a flask in which ozone is decomposing to oxygen, would you expect the flask to
What is the mathematical relationship among the different characteristics of light waves? State the meaning of each of the terms in the equation.
What kind of information does a wave function give about an electron in an atom?
What is the notation for the subshell in which n = 4 and l = 3? How many orbitals are in this subshell?
What is the general shape of an s orbital? of a p orbital?
Which of the following statements is (are) true?I. The product of wavelength and frequency of light is a constant.II. As the energy of electromagnetic radiation increases, its frequency
Of the following possible transitions of an electron in a hydrogen atom, which emits light of the highest energy?a. Transition from the n = 1 to the n = 3 levelb. Transition from the n = 1 to the n =
What wavelength of electromagnetic radiation corresponds to a frequency of 3.46 × 1013 s-1?a. 8.66 × 10-6 mb. 1.15 × 105 mc. 7.65 × 10-29 md. 9.10 × 10-6 me. 8.99 × 10-6 m
Calculate the frequency associated with light of wavelength 434 nm. (This corresponds to one of the wavelengths of light emitted by the hydrogen atom.)
At its closest approach, Mercury is 77.3 million km from Earth. How long would it take to send a radio message from a space probe of Mercury to Earth when the planets are at this closest distance?
What is the energy of a photon corresponding to radio waves of frequency 1.490 × 106/s?
Molybdenum compounds give a yellowish-green flame test. The atomic emission responsible for this color has a wavelength of 551 nm. Obtain the energy of a single photon of this wavelength.
Selenium atoms have a particular transition that emits light of frequency 1.53 × 1015 Hz. (Hz is the abbreviation for hertz, which is equivalent to the unit/s, or s−1.) Is this light in the
Calculate the frequency of electromagnetic radiation emitted by the hydrogen atom in the electron transition from n = 6 to n = 3.
Calculate the shortest wavelength of the electromagnetic radiation emitted by the hydrogen atom in undergoing a transition from the n = 4 level.
At what speed must a neutron travel to have a wavelength of 10.6 pm?
What is the de Broglie wavelength of an oxygen molecule, O2, traveling at 535 m/s? Is the wavelength much smaller or much larger than the diameter of an atom (on the order of 100 pm)?

Showing 400 - 500 of 1219