8.1 5) Based on the octet rule, iodine most likely forms an __________ ion. A) [pic] B) [pic] C) [pic] D) [pic] E) [pic] Answer: E Diff: 1 Page Ref: Sec. 8.1 6) There are __________ unpaired electrons in the Lewis symbol for an oxygen atom. A) 0 B) 1 C) 2 D) 4 E) 3 Answer: C Diff: 1 Page Ref: Sec. 8.1 7) How many unpaired electrons are there in the Lewis structures of a [pic] ion?
Object A has a net charge of excess electrons. Object B is grounded. Which object is at a higher potential? A) A B) B C) Both are at the same potential. D) cannot be determined without more information Answer: B Diff: 2 Type: BI Var: 1 Page Ref: Sec.
Lab Partner: Jason Wallace 02/17/09 LAB ABSTRACT: In this experiment unknown substances were identified by performing different flame tests on known substances. The substances identity was obtained by placing salt solutions of a metallic ion and observing the color of the emitted photon light. INTRODUCTION: By placing atoms of a substance into a flame it can absorb energy and jump into an excited state; called a quantum jump. After absorbing energy and leaping into an excited state, the atoms return back to their original ground state by emitting a photon of light. According to the law of conservation of energy the same amount of energy used to make the quantum jump is released when the photon light is emitted.
tert-Butyl chloride is a colourless, liquid organic compound at room temperature and it is highly flammable and volatile. Tertiary alcohols can be converted to their corresponding alkyl chlorides by the addition of concentrated hydrochloric acid to the alcohol. In this experiment, concentrated HCl is added to tert-butyl alcohol to produce tert-butyl chloride via SN1 reaction. R3COH > R2CHOH > RCH2OH > CH3OH Tertiary alcohols react readily with HX alone to form alkyl halide, while secondary and primary require catalyse in the halo hydrogenation reaction. Zinc Chloride acts as the catalyst in the reaction.
3. What is the relationship between a photon and a quantum leap? • When a quantum leap occurs, a single photon is emitted. 4. Using the periodic table, determine the result of the following calculation: the number of electrons in the outer shell of a hydrogen atom minus the number of electrons in the outer shell of a helium atom plus the number of electrons in the outer shell of a hydrogen atom.
As Model Science (2011) explains, the experiment will show that as the salt with the metal is “burned, the electrons will be excited (i.e., move to another energy level) and as these electrons fall back from one energy level to another, they will emit photons of light. These photons will have different colors depending on the element and its discrete energy levels”. In other words, “different wavelengths of light (colors) will be emitted when the electrons of different elements go down the step(s) between their energy level(s). In addition, each element will have its own set of energy levels and therefore each will have its own color or set of colors (Model Science, 2011)”. As an example, Model Science (2011) provided “sodium burns orange, potassium -purple/blue, barium - green, and lithium – red”.
This is a neutralization reaction between a strong acid and strong base. Therefore the heat of reaction (∆H2) is called as the heat of neutralization of HCl and NaOH solutions. The ∆H2 calculated from this experiment is -6.6944KJ/mol. This is because the enthalpy changes when one mole of H+ ions from an acid (HCl) reacts with one mole of OH- from an alkali (NaOH) to form one mole of water molecules under the stated conditions of the experiment. In the final reaction of the experiment (Part C), solid NaOH will react with an aqueous solution of HCl.
6. Why does CO2 have a much lower boiling point than NO2? CO2 is a linear molecule, and is not polar, and therefore experiences only dispersion forces with other CO2 molecules. NO2 is bent and polar, and therefore interacts with other NO2 molecules via a relatively strong dipole-dipole force. This means that it will require more thermal energy to break free from these intermolecular forces, i.e.
When atoms bond together they share or transfer electrons to achieve a more stable electron arrangement, often a full outer main level of electrons, like the noble gases. There are three types of strong chemical bonds: 1.__ionic______, 2.____covalent____ and metallic IONIC bonding • Ionic bonding occurs between metals and non-metals • Metal atoms 3. ___lose___ electrons • Non-metal atoms gain electrons • Positive and negative ions are formed Sodium chloride has ionic bonding. [pic] • The sodium ion is positively charged because it has lost a negative electron
When approaching the electrophile, the nucleophile comes from the opposite side of the leaving group (backside attack). As the nucleophile attaches, the leaving group simultaneously departs (concerted rxn), leaving a new molecule with an inverted stereocenter configuration from the original. Good leaving groups are those that are most easily replaced by the nucleophile, usually being weak bases and small in size (halogens). The weaker the base, the less inclined the leaving group is to ‘stick’ with the substrate and more likely it is to leave when a stronger nucleophile is introduced. Since SN2 reactions are concerted, the rate of the reaction can be directly related to the concentrations of the substrate and nucleophile (Rate = k[sub][nuc]) in solution.