Final Exam Chem 121

Final Exam Chem. 121 Chapter 1 Exam What is a property of both gases and liquids? Which of the following pairs of properties are both properties chemical properties? -Freezes at 109 C and nonflammable -Decomposes at 500 C and reacts with bromine -Poor conductor of heat and is reddish brown in color -Has a low density and is very hard When a substance undergoes a chemical change it is always true that: -It liquifies -It changes from a solid to a gas -It is converted to a new kind of matter with a different composition -The temperature of the substance increases The description "two substances present, two phases present" is correct for what type of mixture? An element is a substance that... A pure substance F is found to change upon heating into two new pure substances M and Y. Both M and Y may be decomposed by chemical means. From this we can conclude that: In which of the following sequences of elements does each of the elements have a one-letter chemical symbol? A) Indium, Carbon, Silver B) Antimony, Boron, Nitrogen C) Iodine, Boron, Tungsten D) Nitrogen, Germanium, Bromine Which of the following statements about atoms is incorrect? A) An atom is the smallest "Particle" of an element that can exist and still have the properties of that element. B) Free isolated atoms are rarely encountered in nature. C) Atoms may be decomposed using chemical change D) Only one kind of atom may be present in a homoatomic molecule. Which of these is incorrect? A) LiCN and triatomic B) N2 and homoatomic C) KCl and heteroatomic D) SiO2 and diatomic In which of the following pairs of chemical formulas do both formulas represent compounds? A) O2 and O3 B) HCN and N2 C) CO2 and O2 D) N2O4 and NO3 Which of the following is a correct description for a sample of ice cubes in water? A) One phase present, one substance present B) One phase present, two substances present C) Two phases present, one substance present D) Two phases present, two substances present Consider the chemical formulas CoI2 and COI2. Is it true that they: A) Contain identical kinds of atoms B) Identify the same compound C) Contain different kinds and numbers of atoms D) Can be described as none of the above The total number of atoms present in one fomula unit of Co2(SO4)3 is (T/F) The determination of a physical property of a substance cause no change in the identity of the substance (T/F) The isolation of the metal iron from its ores involves a series of high temperature reactions in which carbon monoxide is one of the reactants. (T/F) Matter is anything that has mass, occupies space, and can be seen by the naked eye (T/F) The two most abundant elements in the Earth's crust are oxygen and carbon (T/F) Carbohydrates, fats, and proteins all contain the elements hydrogen, oxygen, and carbon (T/F) Substances whose molecules are both diatomic and heteroatomic must be heterogeneous mixtures A classification of matter with only one phase present A substance decomposes upon heating: A) Could be an element or a compound B) Could be an element but not a compound C) Could be a compound but not an element D) Could not be an element nor a compound A substance is melted: A) Could be an element or a compound B) Could be an element but not a compound C) Could be a compound not an element D) Could not be an element nor a compound Which of the following substances is both homoatomic and tetraatomic? A) HCN B) H2O2 C) P4 D) H2CO3 What mathematical meaning is associated with CENTI? What mathematical meaning is associated with MILLI? What mathematical meaning is associated with MICRO? In which of the following measure numbers are all of the zeros significant? A) 0.0705 B) 0.0004400 C) 3,300,000 D) 3.945900 In which of the following cases is the given measurement rounded to 3 significant figures? A) 479,000 becomes 479 B) 37.98 becomes 38.0 C) 0.02235 becomes 0.0223 D) 49.400 becomes 49,400 How many conversion factors can be derived from the equality 60 seconds = 1 minute ?