CH1410 Practice Exam #1

Transcription

1 CH1410 Practice Exam #1 Section 1 - Multiple Choice - Write the letter of the BEST CHOICE in the space provided. 1. Which state of matter has atomic spacing that is close together and indefinite shape? A) liquid B) solid C) gas D) plasma 2. A pure substance is: A) composed of two or more different types of atoms or molecules combined in variable proportions. B) composed of only one type of atom or molecule. C) composed of two or more regions with different compositions. D) composed of two or more different types of atoms or molecules that has constant composition. 3. How would you classify a clear salt water solution? A) pure substance-compound B) mixture-heterogeneous C) pure substance-element D) mixture-homogeneous 4. All of the following can be considered physical properties EXCEPT A) taste. B) color. C) flammability. D) density. 5. If you hold a solid piece of pure gallium metal in your hand, your body heat will melt the gallium into its liquid form. This illustrates which of the following? A) distillation B) physical change C) chemical change D) chemical property 6. The correct scientific notation for the number is: A) B) C) D) The distance between the two hydrogen atoms in a molecule of water is m. Express this distance in scientific notation. A) m B) m C) m D) m

2 8. The correct number of significant figures in the number is: A) 7" " B) 6" " C) 5" " D) ambiguous 9. Determine the answer for the equation below with correct number of significant figures: A) B) 2.15 C) 2.1 D) = 10. Determine the answer to the following equation with correct number of significant figures: A) B) C) 10.1 D) = 11. The correct prefix for the multiplier is: A) mega." " B) milli."" C) micro." D) nano. 12. Which measurement below represents the heaviest mass? A) 1 mg" " " " B) 1 kg C) 1 pg" " " " D) 1 Mg 13. How many microliters are in 41.0 ml? A) "" " " B) C) 0.041" " " " D) How many calories are there in a 255 Calorie snack bar? A) " " " B) C) 60.9" " " " D) The boiling point of water is " (1) 212 F" (2) 0 C " (3) 373 K A) 1 and 2 only B) 2 and 3 only C) 1 and 3 only D) all of 1, 2, and From the following list of substances and heat capacities, choose the one that will have the lowest final temperature after absorbing kj of heat. Assume identical masses of each substance start at the same initial temperature. A) lead J/g C"" " " B) copper J/g C C) ethanol-2.42 J/g C" " " D) water-4.18 J/g C

3 17. Which of the following is NOT part of Dalton's Atomic Theory? A) Each element is composed of tiny indestructible particles called atoms. B) All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements. C) Atoms combine in simple, whole-number ratios to form compounds. D) Most of the atom's mass and all of its positive charge is contained in a small core called the nucleus 18. Which of the following elements has only 12 protons? A) C" B) Zn" " C) Mg" " D) O 19. Which of the following is NOT a correct name, symbol combination? A) beryllium, Be" " " B) magnesium, Mg C) iron, I" " " " D) manganese, Mn 20. Metals are located where on the periodic table? A) left side" " " " B) right side C) middle" " " " D) along a zig-zag diagonal line 21. Group VIIA elements are also called: A) noble gases." " " B) halogens. C) alkaline earth metals." " D) alkali metals. 22. When an atom loses an electron, the resulting particle is called A) a proton. " " " B) an anion. C) a cation." " " " D) an isotope. 23. How many protons and electrons are present in O2-? A) 8 protons and 8 electrons"" B) 10 protons and 8 electrons C) 8 protons and 10 electrons" D) 16 protons and 8 electrons 24. Isotopes are: A) atoms of the same element that have different number of neutrons. B) atoms of the same element that have different number of protons. C) atoms of the same element that have different number of electrons. D) atoms of the same element that have the same number of neutrons. 25. A fictional element has two isotopes and an atomic mass of amu. If the first isotope is 86 amu and the second isotope has a mass of 90 amu. Which isotope has the greatest natural abundance? A) 86 amu B) 90 amu C) There are equal amounts. D) Not enough information provided.

4 Section 2 - Answer the following computational questions using the information provided. You must show all of your work for full credit. Write your answer in the box provided. 1. How many liters are in 25.8 quarts? (1.00 L = qt) 24.4 L 2. How many cm3 are there in 1.25 ft3? (12 in = 1 ft ; 1.00 in = 2.54 cm) 3.54 x 10 4 cm 3 3. What is the density (g/ml) of an object that has a mass of grams and, when placed into a graduated cylinder, causes the water level to rise from 25.2 ml to 33.6 ml? 1.7 g/ ml 4. The Olympic Games shot put field event uses a 16 pound (lb) shot. What is the mass of the shot in kilograms?!!!! (16 oz = 1 lb and g = 16 oz.) 7.3 kg

5 5. What is the specific heat (J/g C) of a metal object whose temperature increases by 3.0 C when 17.5 g of metal was heated with 38.5 J? q = m x C x T 0.73 J/gºC Section 3 - BONUS QUESTIONS - Answer the following computational questions using the information provided. You must show all of your work for full credit. 1. What is the final temperature of 25.0 grams of water, initially at 22.0 C, after it absorbs 454 J of heat? (The specific heat of water is 4.18J/gºC.) 26.3 ºC 2. A fictional element named Nivadium is found to have three naturally occurring isotopes with the natural abundances shown here: MASS (amu) ABUNDANCE % % % Calculated the atomic mass of Nivadium is amu