Chemistry Unit 1 Test Review

Key

Chemistry Unit 1 test review:

1. Define the following words:

a)Chemistry

b)Accuracy

c)Precision

d)Qualitative measurement

e)Quantitative measurement

f)Mass

g)Scientific Theory

h)Scientific Law

i)Scientific method

j)Significant figure

k)Manipulated variable

l)Responding variable

1. Give 3 examples of a qualitative measurement.

1. Give 3 examples of a quantitative measurement.

1. What is the difference between a scientific law and a scientific theory?

1. Describe the following measurement in terms of accuracy and precision:

1. Measured value is 5.2 mg and the known value = 5.0 mg
2. Measured values are 5.2 mg, 4.9 mg, 5.1 mg (known value = 5.0 mg)
3. Measured values: 6.61 mL, 6.99 mL, 7.25 mL
4. Measured value: 2.134 g/cm3

1. What is the SI base unit for the following measurements

a)Mass-

b)Volume-

c)Energy & work-

d)Amount of a substance-

e)Force -

5. How many significant figures are in the following numbers?

6 Express the Following in Scientific Notation:

a) 0.000 03 =c) 55 000 000 =e) 0.000 007=

b) 8 000 000 =d) 0.002=f) 65 000=

7. Do the Following Calculations and write answers Using Scientific Notation:

a) 0.0005 x 0.002 =b) 5000 000 x 6000 =c) 65 000 x 0.003 =

e) 9 000 / 300 = 3f) 400 / 20 000 =g) 0.008 / 0.00002 =

1. Perform the following calculations and show your answers with the correct number of significant figures.

a) (4.0 x 103 mm) x (1.5 x 102 mm) =

b)(5.5 x 105 Km3) / (3.3 x 103Km) =

c)596,000 mg2 ÷ 0.0023 mg =

d)6.77 kg x 0.9 kg =

1. When a test instrument is calibrated, does its accuracy, precision, or reliability improve

1. Which of the following measurements (of different masses) is the most accurate?

11. Three different people weigh a standard mass of 2.00 g on the same balance. Each person obtains a reading of 7.32 g for the mass of the standard. These results imply that the balance that was used is ____.

12. Which of the following units is NOT an official SI unit?

Which step in the scientific method requires you to use your senses to obtain information?

1. Estimate the following measurements to the correct number of significant figures.

1. Determine the percent error for the following problems:

1. A student measured the specific heat of water to be 4.29 J/g. The literaturevalue of the specific heat of water is 4.18 J/g . What was the student’spercent error?

1. A student took a calibrated 200.0 gram mass, weighed it on a laboratory balance, andfound it read 196.5 g. What was the student’s percent error?

1. Density Practice. Show ALL work with UNITS
2. What is the density of a piece of wood that has a mass of 25.0 grams and a volume of 29.4 cm3?
3. Apiece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams.What is the density of the wood?Would the piece of wood float in water?
4. A cup of gold colored metal beads was measured to have a mass425 grams.By water displacement, the volume of the beads was calculated to be 48.0 mL.Given the following densities,[ Gold: 19.3 g/mL, Copper:8.86 g/mL, Bronze:9.87 g/mL] identify the metal.

Esasy Questions: (I will not give you these answers but you can look them up)

35.Explain how a hypothesis, a theory, and a scientific law are related to observations.

36.Explain the difference between precision and accuracy. Suppose you made three different mass measurements of a sugar sample you knew to have a mass of 1 g. How would you know whether or not the measurements were accurate? How would you know whether or not they were precise? Could the three measurements be precise, but not accurate? Explain.

37.Describe the rules that are used to determine the number of significant figures in the results of addition, subtraction, multiplication, and division.

38.Give an example of an equality and explain how it is used