Density Lab Exam. I. Multiple choice section- write the correct answer for each answer on the line. These are each worth 2 points.

Transcription

1 Names:_Team #: Density Lab Exam I. Multiple choice section- write the correct answer for each answer on the line. These are each worth 2 points. 1.Which of the following is NOT a proper unit of density? a. g/ml b. kg/m 3 c. g/cm 2 d. g/l 2. Which of the following equations is correct for density? a. Density= Pressure/Volume b. Density= Mass/Volume c. Density= Volume x Mass d. Density = Mass/Area 3. If you take a large piece of wood with a density 0.74 kg/m 3 and cut it in half, each half of the wood would have. a. Half the density of original piece b. Twice the density of original piece c. The same density as original piece d. No density 4. If the density of water is 1g/cm 3 then 100 cm of water should have a mass of. a. 100 grams b. 50 grams c. 1 gram d. 100 Kg 5. A small piece of sand sinks in water, that is because a. Sand is solid b. Sand is less dense than water c. There is more water than sand d. Sand is more dense than water 6. A carrot floats in salt water but sinks in fresh water. This is because a. Salt water is more dense than fresh water b. Fresh water is more dense than salt water c. The carrot is more dense than salt water d. The densities of the water are the same 7.A solution is made by dissolving some salt in a beaker of water. The salt is referred to as a. Solute b. Filtrate c. Solution d. Solvent 8.A solution is made by dissolving some salt in a beaker of water. The salt is referred to as a. Solute b. Filtrate c. Solution d. Solvent

2 9. 25mL of a solution is equal to how many L of solution? a. 0.25L b. 25? c L d. 2.5L 10. Which of the following is the correct equation for Pressure? a. Pressure = Force x Volume b. Pressure = Mass/Volume c. Pressure = Force/Area d. Pressure = Force/Volume 11. Which of the following does not measure pressure? a. Barometer b. McLeod guage c. thermocouple d. Manometer 12. If two objects have the same mass but different volumes. a. The larger volume item has lower density b. They have the same density c. The larger volume item has higher density d. The larger volume item has twice the density 13. What is the concentration, in % (m/v) of a solution containing 15.0 g KCl in ml solution? a. 5.00% b. 2.00% c % d. 2.50% 14. A 5.00 ml sample of solution has 2.8 x 10-4 g of calcium ions. The ppm concentration is a. 18ppm b. 56ppm c. 2.8 x 10-1 ppm d. 2.8 x 10 2 ppm 15. As pressure decreases in gases, usually resulting in an in volume and a in density. a. increase/decrease b. increase/increase c. decrease/increase d. decrease/decrease 16. Water is unusual because its density is. a. Greatest as a solid b. Greatest as a liquid c. greatest as a gas d. The same in each phase % of an iceberg is visible in the water. That means it s density is closest to. a. 0.1g/cm 3 b. 0.9g/cm 3 c. 1.0g/cm 3 d. 10g/cm 3

3 18. How do you change the mass of an object? a. Move it to the moon b. Add or take away matter c. make Earth spin faster d. Change it s temperature 19.What is a unit of pressure called? a. Pascal b. Newton c. Meter d. Bernoulli 20. One way to increase pressure on a gas is to a. Decrease temperature b. Increase volume c. add gas particles d. Lower kinetic energy 21. Which of the following is a temperature that wouldn t need to be converted to use the ideal gas law equation? a. 27 degrees Fahrenheit b. 321 degrees Kelvin c. 121 degrees Celsius d. 0 degrees Celsius 22. Buoyant Force is an upward force that is equal to the weight of the fluid it. a. Is placed in b. displaces c. exfoliates d. Slows down 23. Objects if their weight is equal to their buoyant force a. Move b. ink c. float d. accelerate 24. What unit is n measured in the equation pv=nrt a. pascals b. degrees c. cm 3 d. Mols 25. If the molar mass of Ammonia (NH 3 ) is 17g/mol and you have 51 grams of Ammonia, how many moles of Ammonia do you have? a. 34 mol b. 2 mol c. 3 mol d. 68 mol 25. Assuming mass of a sample of aluminum is kg and it is occup 4.44cm 3 of space, what is aluminum s density? a. 2.7g/cm 3 b g/cm 3 c. 2.7kg/cm 3 d. 2.7g/m 3

4 Calculation portion. Each of the following questions are worth 3 points. You get a point for showing work, correct answer to the correct significant digits, and correct unit. Put correct answer on the line provided 1. A chef fills a 50.0 ml container with 43.5 g of cooking oil. What is the density of the oil? 2. A rectangular block of copper metal weighs 1896 g. The dimensions of the block are 8.40 cm by 5.50 cm by 4.60 cm. From this data, what is the density of copper? g of iron shot is added to a graduated cylinder containing ml of water. The water level rises to the ml mark, from this information, calculate the density of iron

5 4. A sample of copper (Cu) has a density of 8.92 g/cm 3 and measures 4.00 cm long, 2.00 cm high and 1.00 cm thick. What is the mass in grams of this block of copper? 5. What is the concentration of a solution, in parts per million, if 15.25g of NaCl is added to 800g of H 2 O? g of potassium fluoride (KF) are dissolved to make 0.500L of solution. Calculate the molarity of the solution.

6 7. According to the ideal gas law, If you have 10.0 moles of a gas at a pressure of 6.50 atm, and a volume of 15.0 liters, what is the temperature of the gas? 8. If I contain 4.00 moles of gas in a container with a volume of 25.0 liters and at a temperature of 375 K, what is the pressure inside the container?

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