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Final Exam Review. Chemistry – First Semester. “Matter is made up of atoms. Atoms have tiny positive centers containing protons and neutrons.” The above statement is a/an A. inference B. hypothesis C. theory D. observation Answer: C. In order to become a theory, a hypothesis should be
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Final Exam Review Chemistry – First Semester
“Matter is made up of atoms. Atoms have tiny positive centers containing protons and neutrons.” The above statement is a/an A. inference B. hypothesis C. theory D. observation Answer: C
In order to become a theory, a hypothesis should be A. obviously accepted by most people. B. a fully functional experiment. C. in alignment with past theories. D. repeatedly confirmed by experimentation Answer: D
What is the density of a substance which has a volume of 100.0 mL and a mass of 85.5 g? Answer: 0.855 g/mL
How many significant digits does this measurement have? 95.50 mL Answer: 4
Calculate the % error of a measurement (0.90 g/mL) if the true value is 1.0 g/mL. Answer: 10%
Which of these statements is NOT true about matter and energy? A. All matter possesses energy. B. Matter can be changed into energy and energy can be changed into matter. C. Energy can only be transferred from one sample of matter to another when they are in direct contact with one another. D. The total amount of matter and energy in the universe remains the same; they just change from one form to another. Answer: C
Which of these is an exothermic process? Melting of ice Combustion (burning) of gasoline Photosynthesis Evaporation of water Answer: B
An endothermic reaction releases energy to the surroundings. causes a temperature increase in its surroundings. absorbs energy from its surroundings. produces substances that have a lesser energy than the starting materials. Answer: C
Which is true about metals? A. They are found on the right side of the periodic table. B. They are poor conductors . C. They have higher densities compared to non-metals. D. Most of them are liquids and gases at room temperature. Answer: C
The nucleus of an atom is negatively-charged accounts for most of the atom’s mass occupies most of the atom’s volume contains electrons and protons Answer: B
Give the number of protons, electrons and neutrons of 158O. Answer: electrons- 8, protons- 8, neutron-7
Which of these is NOT true of the atom? It may be positively or negatively-charged. It contains the same number of protons and electrons. It is mostly empty space. It has a very dense center. Answer: A
Isotopes of the same element always have the same A. atomic number B. mass number C. atomic mass D. number of neutrons Answer: A
Some isotopes easily break down and emit radiation. Which type of radiation is the least penetrating? beta alpha X-ray gamma Answer: B
When a metal is heated in a flame, the flame turns a distinctive color. This information can be applied in the study of stars because A. star color tells us how far it is from the earth. B. the color of the star tells us how big it is. C. the color of the star tell us how old it is. D. the color spectra of a star show which elements are present in it. Answer: D
Draw the Lewis Dot diagram of carbon Answer: C
Which element do you expect to have the same valence electrons as carbon? calcium iron chlorine silicon Answer: D
Write the electron configuration of potassium. Answer: 1s2 2s2 2p6 3s2 3p6 4s1
Which of these is a halogen? helium carbon lithium iodine Answer: D
To which family does the element krypton belong? Alkali metal Alkaline-earth metal Transition Metal Noble gases Answer: D
Which of these is true of noble gases? They have 8 valence electrons except for helium. They belong to Group 2A. They easily form bonds with other elements. They have very low ionization energies. Answer: A
In general, how do atomic masses change throughout the periodic table of elements? They increase from left to right and top to bottom. They increase from left to right and bottom to top. They increase from right to left and top to bottom. They increase from right to left and bottom to top. Answer: A
Why is cobalt (Co) placed before nickel (Ni) on the periodic table even though its atomic mass is higher than nickel’s? Cobalt has more electrons. Nickel has a higher density. Cobalt was discovered first. Nickel has one more proton. Answer: D
Which element is the least electronegative? Nitrogen Phosphorus Oxygen Sulfur Answer: B
Which type of chemical bond exists between a metal and a non-metal? Ionic
Metallic substances are usually good conductors of electricity because of the loosely bonded electrons that move around the metal structure of the closely packed atoms of the strong bonds that exist between atoms of the weak bonds that exist between atoms Answer: A
Which of these is NOT an electrical conductor? aluminum Alcohol (C2H5OH) solution Potassium chloride (KCl) solution Hydrochloric acid (HCl) solution Answer: B
Which element can form long chains of atoms by forming single, double and triple bonds with itself? oxygen B. nitrogen C. carbon D. hydrogen Answer: C
What is the correct formula of sodium bromide? NaBr B. Na2Br C. NaBr2 D. Na2Br2 Answer: A
What is the chemical formula for copper (II) nitrate? Cu(NO3)2
Give the name of CaCl2 Calcium Chloride
Give the name of FeSO4 Iron (II) sulfate
What is the correct formula of sodium bromide? NaBr B. Na2Br C. NaBr2 D. Na2Br2 Answer: A
Which of these is an acid?H2SO4KOHK2SO4 Answer: H2SO4
Which is a polar covalent bond?A. N-HB. As-HC. O-OD. Cl-Cl A
How many non-bonding (unshared) pairs of electrons does sulfur have in H2S? 2
Which of these is a polar molecule?A. CO2B. SF6C. CH4D. PCl3 D
Predict the shape of the NH3. Trigonal Pyramidal
These pairs of atoms are covalently bonded. Arrange them according to increasing polarity.A. N-OB. Cl-FC. C-HD. C-Cl C,D,A,B
NH3 + HCl → NH4ClHow many grams of NH3 is needed to produce 25 g of NH4Cl? 8.0 g of NH3
