Test 1 Review Questions Chapter 2
59-61: 1-6, 8-9, 13-14, 17-19, 24-25a, 29-30, 35-42
63: 1-7, 12
1. How does quantitative information differ from qualitative information? Quantitative is numerical and Qualitative is descriptive.
2. What is a hypothesis? An explanation that is based on prior scientific research or observations and that can be tested.
3. a. What is a model in the scientific sense? A pattern, plan, representation, or description designed to show the structure or workings of an object, system, or concept
b. How does a model differ from a theory? A model explains one concept while a theory explains a body of facts and phenomena.
4. Why is it important for a measurement system to have an international standard? So that when scientists test each other’s experiments there will be a lower chance of mistakes.
5. How does a quantity differ from a unit? Use two examples to explain the difference. A quantity is a type of measurement while a unit represents a way to measure something. Ex1-A quantity is length; a unit used to measure length is a meter. Ex2- A quantity is mass; kilograms are used to measure mass.
6. List the seven SI base units and the quantities they represent. Meter(length), Kilogram(mass), Seconds(time), Kelvin(temperature), Mole(amt. of substance), Ampere(electric current), Candela(Luminous intensity.)
8. Identify the SI unit that would be most appropriate for expressing the length of the following. a. width of a gymnasium- meter
b. length of a finger-centimeter
c. distance between your town and the closest border of the next state -kilometer d. length of a bacterial cell- attometer
9. Identify the SI unit that would be most appropriate for measuring the mass of each of the following objects. a. table- kilograms
b. coin- centigrams
c. a 250 mL beaker- grams
13. a. Why are the units that are used to express the densities of gases different from those used to express the densities of solids or liquids? Because gases are 1000times less dense than liquids and solids b. Name two units for density. Cubic centimeters and grams
c. Why is the temperature at which density is measured usually specified? Density varies with temperature
14. a. Which of the solids listed in Table 4 will float on water? Cork, butter, ice, gasoline, ethyl alcohol, kerosene, turpentine b. Which of the liquids will sink in milk? Mercury, lead, copper, diamond, bone, sucrose
17. Find the density of a material, given that a 5.03 g sample occupies 3.24 mL. (Hint: See Sample Problem A.) 1.55g/mL
18. What is the mass of a sample of material that has a volume of 55.1 cm3 and a density of 6.72 g/cm3? 370.27g
19. A sample of a substance that has a density of 0.824 g/mL has a mass of 0.451 g. Calculate the volume of the sample.0.547mL 24. Compare accuracy and precision. Accuracy describes how close a measurement is to the true value of the quantity measured while precision is the exactness of a measurement.
25. a. Write the equation that is used to calculate percentage error. Value(experimental)- Value(accepted
29. Round each of the following measurements to the number of significant figures indicated. a. 67.029 g to three significant figures- 67.0g
b. 0.15 L to one significant figure-0.2L
c. 52.8005 mg to five significant figures- 52.801mg
d. 3.174 97 mol to three significant figures-3.17mol
30. State the rules governing the number of significant figures that result from each of the following operations. a. addition and subtraction- When adding or subtracting decimals, the answer must have the same number of digits to the right of the decimal point as there are in the measurement having the fewest digits to the right of the decimal point. b. multiplication and division-3SF
35. A student measures the mass of a sample as 9.67 g. Calculate the percentage error, given that the correct mass is 9.82 g. (Hint: See Sample Problem C.)
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