ACS Chem Final – Flashcards
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| _____and _____have most of the mass of the atom but occupy very little volume of the atom. |
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| protons and neutrons |
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| Atoms can only be isoelectronic with atoms that are? |
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| "bigger" than them |
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| Look at _____not____when it asks to determine which one has the same number of electrons. |
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| ions, atoms |
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| Transition metals have electrons corresponding to their_____. If it is an ion, then add or subtract based on if it is a cation or an anion. |
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| atomic number |
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| How does an atom of Magnesium (Mg) differ from a magnesium ion (Mg 2+)? |
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| a magnesium ion has an inert gas electron configuration; the atom does not |
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| HOw is the a sodium ion different from a sodium atom? |
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| a sodium ion has fewer electrons than the atom |
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| An atom of the element with atomic number 84 and mass number 199 emits an alpha particle. The residual atom after this charge has an atomic number of ____and a mass number of ____. |
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| 82, 195 |
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| In effecting nuclear changes by bombarding target nuclei with positively charged alpha particles, it is necessary to accelerate these particles to high speed because it is necessary to ______. |
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| overcome the force of repulsion of the nucleus |
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| What did Milkman determine? |
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| the magnitude of the charge of an electron |
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| The maximum number of electrons that can occupy an orbital labeled dxy is ___. |
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| 2 |
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| HOw many unpaired electrons would there be in an Fe 2+ ion? |
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| 4 |
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| The existence of discrete (quantized) energy levels in an atom may be inferred from _____. |
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| atomic line spectra |
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| Which set of quantum numbers is consistent with n=4? |
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| l=3 m=-3 ms= +1/2 (l is always one less than n) |
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| The orbitals of 2p electrons are often represented as being _____ |
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| dumbbell shaped |
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| The molecule of the type ML4 consists of 4 single bonds and no lone pairs. What structure is it expected to assume? |
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| tetrahedral |
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| The shape that most correctly desribes the NF3 molecule is _____ |
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| trigonal pyrimidal |
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| What is an example of a planar molecule? |
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| CO3 ^2- |
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| What is an example of a linear molecule? |
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| CO2 |
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| What is the shape of the XeF4 molecule? |
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| square planar |
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| Which concept describes the formation of 4 equivalent, single, covalent bonds by carbon it is compound that resemble methane CH4? |
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| hybridization |
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| Which type of hybrid orbital is used in CO2? |
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| sp |
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| Which compound would be exepected to have the largest dipole moment? |
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| SO2 (bent) |
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| youtube bond angles |
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| Knowing that F is more electronegative than either B or P, what conclusion can be drawn from the fact that BF3 has no dipole moment but PF3 does? |
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| The BF3 molecule must be trigonal planar |
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| How many valence electrons are represented in the Lewis dot structure for SO2? |
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| 18 (sulfur has 6 and oxygen has 6x2=12) |
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| What is unique about compounds NO2 and XeF4? |
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| they both violate the octet rule |
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| The boiling point of H20 is different than other members of the group VIA hydrides can be explained by ______ |
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| hydrogen bonding |
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| What is an example of something that has both covalent and ionic bonds? |
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| Mg(CN)2 |
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| The complete lewis structure of COCl2 will have ____. |
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| at least one double bond |
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| The limiting reagent in a particular reaction can be recognized because it is the reagent that is ______ in a reaction. |
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| used up first |
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| The amount of product that will be formed if all of the limiting reagent is used up is called the _____. |
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| theoretical yield |
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| A particular solid is soft, a poor conductor of heat and electricity, and has a low melting point. Generally, such a solid is classified as _____ |
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| molecular |
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| Carbon dioxide, CO2, in the form of dry ice would be classified as _____. |
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| molecular solid |
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| The melting point of an impure compound is generally _____. |
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| lower than that of a pure solid |
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| What factor affects the vapor pressure of a liquid? |
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| temperature |
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| A gas or vapor may be liquified only at temperatures ______ |
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| at or below the critical tempertaure |
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| Which set of temperature and pressure conditions will cause a gas to exhibit the greatest deviation from ideal gas behavior? |
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| -100 degrees C and 4atm |
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| What is the number of nearest neighbors in a body centered cubic lattice? |
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| 8 |
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| When a material in the liquid state is vaporized and then condensed to a liquid, the steps in the process are respectively______and_____. |
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| endothermic and exothermic |
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| More heat is derived from cooling one gram of steam at 100 degrees Celsius to water at 50 degrees Celsius than from cooling one gram of liquid water at 100 degrees celsius to 50 degrees celsius because ______. |
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| the heat of condensation is evolved |
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| In a bomb calorimeter, reactions are carried out at _____. |
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| constant volume |
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| The standard enthalpy change for the formation of silver chloride from its elements is ______than the enthalpy change for the formation of silver bromide. |
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| more exothermic |
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| In what process is entropy decreased? |
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| freezing water |
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| When a liquid evaporates, which is true about the signs of the enthalpy and entropy changes? |
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| delta H is postive and delta S is positive |
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| A particular chemical reaction has a negative delta H and a negative delta S. what does this mean? |
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| the reaction becomes spontaneous as temperature decreases |
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| What metal reacts with concetrated NaOH to produce hydrogen gas? |
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| aluminum |
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| What gas is most effectively collected by the displacement of water? |
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| oxygen |
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| What gas is the least soluble in water? |
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| H2 |
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| What gas is the predominant nitrogen-containing pollutant in the atomosphere? |
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| NO2 |
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| Helium is preferable to hydrogen for filling baloons because helium is ______. |
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| chemically inert |
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| Forming colored compounds, showing a variety of oxidation states, having individual atoms with one or more unpaired electrons are all characterstics of ______. |
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| transition metals |
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| Potassium permanganate and iodine are similar in _____. |
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| color |
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| Which natural process tends to change the free nitrogen into fixed nitrogen? |
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| lightning storms |
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| When glucose (C6H12O6) is completely oxidized with excess oxygen what are the products? |
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| H2O and CO2 |
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| What iion may form a scummy precipitate with ordinary soap? |
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| Ca2+ |
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| What statement best reflects the orginization of the modern periodic table? |
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| NOnmetallic properties tend to predominate for elements at the far right portion of the table |
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| An element forms a baic oxide with the formula XO and a hydride with the formula XH2.The hyrdride reacts with water to give oxygen.The element X could be ____. |
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| Calcium |
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| The size of metal atoms does what in realtion to the periodic table.... |
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| generally increases from top to bottom in a group in the periodic table |
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| What is the periodic trend for atomic radius? |
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| it increases as you move to the left and the down the periodic table |
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| What happens when a bromine atom becomes a bromide ion? |
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| the bromide ion is larger than the bromine atom |
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| youtube first ionization energy and oxidation states |
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| When an acid soution is titrated with a standard base solution, separate burets are sometimes used for each solution. Which mistake would necessitate emptying and refilling burets, and starting the tritration over? |
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| allowing drops of distilled water to stay in the burets while filling them |
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| adding and subtracting sig figs? |
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| least number of decimal places |
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| To deliver a 25.00 mL liquid sample most precisely, which piece of glassware would you use? |
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| volumetric pipet |
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| A student determined the percent water in a sample. In four trials, values of 16.145, 16.156, 16.160, and 17.279 were obtained for the percent water in a sample. How would you chose a value to report for the percent water in the sample? |
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| average the three "sixteen" values because they are all near each other |
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| accuracy is how close something is to the expected value. precision is how often sometthing is near the same number |
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| What experimental evidence clearly illustrates teh oxidizing property of chlorine, Cl2? |
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| the reaction of chlorine with sodium bromide solution, resulting in the displacement of bromine |
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| The best method of transferring a coarsely powdered solid to a six inch test tube is to:______. |
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| pour it from a creased square of paper |
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| You have a beaker nearly full of gasoline on your laboratory table and it catches on fire. What should you do? |
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| cover the beaker with a wet cloth |
