Chem Review PDF

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This review questions included question about calculating atomic mass, calculating percent composition by mass, calculating heat released and many more!
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Questions 1. Show a numerical setup for calculating the percent composition by mass of silicon in SiO 2.

2. In nature, 1.07% of the atoms in a carbon sample are C-13 atoms. Show a numerical setup for calculating the number of C-13 atoms in a sample containing 3.28 x 1024 atoms of carbon.

The two naturally occurring isotopes of antimony are Sb121 and Sb-123. The table shows the atomic mass and percent natural abundance for these isotopes. 3. Show a correct numerical setup for calculating the atomic mass of antimony.

4. Show a correct numerical setup for calculating the percent composition by mass of antimony in stibnite, Sb2S3. (gram-formula mass = 340g/mol).

5. Show a numerical setup for calculating the atomic mass of potassium.

A bracelet has a mass of 30.1 grams and was at a temperature of 21°C in the classroom. A student wore the bracelet and it reached a temperature of 33°C. Later, the student removed the bracelet and placed it on a desk at home, where it cooled from 33°C to 19°C. The specific heat capacity of copper is 0.385 J/g•K. 6. Show a numerical setup for calculating the amount of heat released by the bracelet as it cooled on the desk. A homeowner has a water quality report prepared for a sample of water taken from pipes in the home. According to the report, the 550 gram sample contains 6.75 x 10-4 grams of dissolved Cu2+ ions. 7. Show a numerical setup for calculating the concentration, in parts per million, of dissolved Cu 2+ ions in the sample of water tested.

Paintball is a popular recreational activity that uses a metal tank of compressed carbon dioxide or nitrogen to launch small capsules of paint. A typical tank has a volume of 508 cubic centimeters. A 340g sample of

carbon dioxide is added to the tank before it is used for paintball. At 20°C, this tank contains both CO2(g) and CO2(ℓ). After a paintball game, the tank contains only CO2(g). 8. After the paintball game, the tank has a gas pressure of 6.1 atmospheres and is at 293 K. If the tank is heated to 313 K, the pressure in the tank will change. Show a numerical setup for calculating the pressure of the gas in the tank at 313 K.

In a titration, 50.0 milliliters of 0.026 M HCl (aq) is neutralized by 38.5 milliliters of KOH (aq). 9. Show a numerical setup for calculating the molarity of the KOH (aq).

Cylinder A has a movable piston and contains hydrogen gas. An identical cylinder, B, contains methane gas. The diagram below represents these cylinders and the conditions of pressure, volume, and temperature of the gas in each cylinder. 10. Show a numerical setup for calculating the volume of the gas in cylinder B at STP.

11. Show a numerical setup for calculating the mass of carbon dioxide in a 100.0-gram sample of air taken in 1980.

The label of one aspirin bottle indicates that the accepted mass of acetylsalicylic acid in each tablet is 325 milligrams. The mass of acetylsalicylic acid in one aspirin tablet is determined to be 320 milligrams. 12. Show a numerical setup for calculating the percent error for the mass of acetylsalicylic acid in this aspirin tablet.

13. Show a numerical setup for calculating the change in the thermal energy (heat) of the water in the bottle from 7 a.m. to 3 p.m.

A total of 1.4 moles of sodium nitrate is dissolved in enough water to make 2.0 liters of an aqueous solution.

The gram-formula mass of sodium nitrate is 85 grams per mole. 14. Show a numerical setup for calculating the mass of the solute used to make the solution.

15. Show a correct numerical setup for calculating the molarity of the solution.

The gram-formula mass of KAl(SO4)2•12H2O is 474 grams per mole. 16. Show a numerical setup for calculating the percent composition by mass of water in KAl(SO4)2•12H2O.

In a titration, a few drops of an indicator are added to a flask containing 35.0 milliliters of HNO3 (aq) of unknown concentration. After 30.0 milliliters of 0.15 M NaOH (aq) solution is slowly added to the flask, the indicator changes color, showing the acid is neutralized. 17. Show a numerical setup for calculating the concentration of the HNO3 (aq) solution.

Ascorbic acid has a molecular formula of C6H8O6 and a gram-formula mass of 176 grams per mole. 18. Show a numerical setup for calculating the percent composition by mass of oxygen in ascorbic acid.

19. Show a numerical setup for calculating the atomic mass of copper.

Heat is added to a 200.-gram sample of H2O (s) to melt the sample at 0°C. Then the resulting H2O (ℓ) is heated to a final temperature of 65°C. 20. Show a numerical setup for calculating the total amount of heat required to raise the temperature of the H2O (ℓ) from 0°C to its final temperature.

21. Show a correct numerical setup for calculating the final volume of the helium gas sample.

22. Show a correct numerical setup for calculating the atomic mass of sulfur.

In a chemical reaction H2(g) is produced with a volume of 112 milliliters and a pressure of 1.00 atmosphere at 298 K. 23. Show a correct numerical setup for calculating the volume of the H2(g) produced if the conditions are changed to STP

After a strenuous workout, people often quench their thirst with sports drinks that contain NaCl and KCl. A single 250gram serving of one sports drink contains 0.055 gram of sodium ions. 24. Show a correct numerical setup for calculating the concentration of sodium ions in this sports drink, expressed as percent by mass.

In a titration, 15.65 milliliters of a KOH (aq) solution exactly neutralized 10.00 milliliters of a 1.22 M HCl(aq) solution. 25. Show a correct numerical setup for calculating the molarity of the KOH (aq) solution.

An unsaturated solution is made by completely dissolving 20.0 grams of NaNO3 in 100.0 grams of water at 20.0°C. 26. Show a correct numerical setup for calculating the number of moles of NaNO3 (gram-formula mass = 85.0 grams per mole) used to make this unsaturated solution....