Chapter 1 Matter and Measurement 1. Which of the following is NOT an example of matter? (a). Coal (b). Elemental oxygen (c). Trees (d). Heat Explanation: Heat is an example of energy; matter has a fixed shape and occupies space. 2. The law of constant composition applies to (a). Homogeneous mixtures (b). Solutions (c). Compounds (d). None of the above Explanation: The law of constant composition states that the elemental composition of a pure compound is always the same. 3. Which one of the following can be easily separated into its components with simple techniques like filtration or decantation? (a). Heterogeneous mixtures (b). Homogeneous mixtures (c). Solutions (d). Compounds Explanation: Heterogeneous mixtures are those where the individual components are easily distinguished from one another. 4. How many femtoseconds are in a second? (a). 1 x 10-1 (b). 1 x 10-12 (c). 1 x 10-15 (d). 1 x 10 +15 Explanation: Since the prefix femto means 1 x 10-15, there will be 1 x 10 +15 femtoseconds in one second. Copyright 2006 Dr. Harshavardhan D. Bapat 1
5. The number 0.0005678 expressed in scientific notation is: (a). 5.678 x 10 4 (b). 5.67 x 10-7 (c). 5.678 x 10-4 (d). 5.678 10-3 Explanation: Since this number is less than one star moving the decimal point to the right until there is ONE non-zero number to the left of the decimal point. Write the rest of the number as is. Write the exponent as the number of places the decimal point was moved. 6. Solids have a shape and are not appreciably. (a). Definite, compressible. (b). Definite, incompressible. (c). Indefinite, compressible Explanation: These are physical properties of solids. 7. Which of the following can have a variable composition? (a). A homogeneous mixture. (b). A heterogeneous mixture. (c). A pure element. (d). Both a homogeneous and a heterogeneous mixture. Explanation: A variable composition means that in a mixture the amounts of the components present are different from one part of the mixture to the next. 8. The SI unit of mass is (a). The pound (b). The gram (c). The kilogram (d). The mole. 9. An element cannot (a). be part of a homogeneous mixture (b). be part of a heterogeneous mixture (c). be separated from other substances by chemical means. (d). interact with other elements to form compounds Copyright 2006 Dr. Harshavardhan D. Bapat 2
10. Which one of the following is not an intensive property? (a). The identity of the element (b). Density (c). Mass (d). Melting point Explanation: All other answers are independent of the amount of a substance present while mass is dependent on how much of a substance is present making mass an extensive property. 11. Which of the following is an intensive property? (a). Volume (b). Mass (c). Temperature (d). Heat content Explanation: All other answers are dependent of the amount of a substance present while the temperature is independent on how much of a substance is present making temperature an intensive property. 12. Which of the following is the smallest distance? (a). 21 m (b). 2.1 x 10 2 cm (c). 21 mm (d). 2.1 x 10 4 pm Explanation: Even though 2.1 x 10 4 is the largest number in this question, the units of pm (picometers) are the smallest units here, making it the smallest distance. 13. Precision of a measurement refers to (a). How close a measurement is to the known value. (b). How close a measured number is to other measured numbers. (c). How close the measurement is to a calculated value. 14. Accuracy of a measurement refers to (a). How close a number is to other measured numbers. (b). How close a number is to the calculated value. (c). How close the measured number is to the known value. Copyright 2006 Dr. Harshavardhan D. Bapat 3
15. Mercury has a density of 13.6 g/cm 3. Mercury exists as a liquid at room temperature. If you drop a piece of lead (the density of lead = 8.0 g/cm 3 ) in a beaker containing mercury will the lead will. (a). float (b). sink (c). not enough information. Explanation: Since the density of lead is less than that of mercury the piece of lead should float. 16. Which of the following number has the same number of significant figures as 2.00910? (a). 2 x 10 6 (b). 39.9 (c). 56.0048 (d). 24.0 Explanation: All the zeroes between non-zero digits are counted and so is the trailing zero in the number 2.00910 giving it six significant figures. 56.0048 is the only number with six significant figures. 17. Expressing a number in scientific notation (a). Changes its value (b). Increases the precision of the number (c). Rounds the number (d). Removes any doubts about any ambiguous zeroes. 18. Of the following numbers the number with most significant zeroes is (a). 0.001 (b). 200.01 (c). 3005.00340 (d). 100,000 Explanation: The number 3005.00340 has 5 significant zeroes while the only significant figure in the number 100,000 is the first digit. Copyright 2006 Dr. Harshavardhan D. Bapat 4
19. Round the number 0.006734 to 2 significant figures (a). 0.67 (b). 0.067 (c). 0.0068 (d). 0.0067 Explanation: Since the digit 3 is less than 5 the digit 7 is retained as is. 20. Round the number 229.613 to 4 significant figures and express the answer in scientific notation (a). 229.6 (b). 22.96 (c). 2.296 x 10-3 (d). 2.296 x 10 2 (e). None of the above Copyright 2006 Dr. Harshavardhan D. Bapat 5