INTRODUCTION In this experiment, the reaction between magnesium solid and hydrochloric acid will be studied. The rate of reaction and the quantity of reaction will be investigated. The factors that affect

2. [Adapted from Crowl 6-9] A barbecue gas cylinder contains 25lb of butane. The cylinder accidentally falls over and ruptures, vaporizing the entire contents of the cylinder. The vapor cloud is ignited, and an explosion occurs. Estimate the overpressure from this explosion 100ft away. Using Table 6-9 in your textbook,what kind of damage is expected. What kind of safeguards could have been implemented in order to prevent this incident?

Many chemical reactions are known in which two substances react in precise mole ratios to form a known product in virtually 100% yield with no side-reactions or unexpected by-products. Such reactions may be studied conveniently by titration, the carefully-measured addition of a solution of one reactant to a known amount of the second reactant until that point at which the precisely correct mole ratio of the two reactants is reached. This point, called the end-point, may be determined with the use of an indicator. In this experiment we will study three acid-base reactions which fall into the category described above. In the first part, weighed samples of oxalic acid will be titrated with a solution of NaOH of unknown concentration. The end-point will be determined with an indicator which remains colorless so long as excess acid is present, but which turns pink when the first drop of excess NaOH is added. The molarity of NaOH can then be calculated. In the second part, a measured volume of vinegar (a solution of acetic acid) will be titrated with the same NaOH solution. Since the molarity of the NaOH solution is now known, the molarity of acetic acid in the vinegar can be calculated. Given the density of vinegar, the percent composition can also be determined. In the third part, weighed samples of an unknown monoprotic acid will be titrated with the standard NaOH solution. From the data gathered, the molar mass of the unknown acid will be determined.

= 0+1866XLO 1) a) A bare Si wafer is oxidized in dry O2 at 1100 °C. The desired final thickness is 50 nm. J i) Find the time required to perform the oxidation, ignoring rapid growth. ii) Find the time required to perform the oxidation, taking rapid growth into account. tox Use Deal-Grove equations - do NOT use oxide growth curves. b) A <111> silicon wafer is oxidised using the following sequence i) 60 mins @ 1000°C in dry O₂. ATB 0,065 [10 1/3 marks] ii) 60 mins @ 1000°C in steam. 0.125 iii) Locally etch 0.1 microns of oxide to create a trench. iv) 30 mins @ 1100°C in dry O2. 0.009 Use growth curves to calculate the oxide thickness after each step. [10 marks c) It is possible to determine the thickness of oxide on oxidised wafers by visual inspection. Describe the method and discuss TWO disadvantages of this technique. [5 marks] d) Discuss FIVE of the features of SiO₂ which account for its widespread use in microelectronics. Breack down $h field [5 marks e) Dry oxidation is much slower than wet oxidation. Discuss briefly any advantages to using dry oxides instead of wet oxides. [3 mark -Excellent stable Passivation Excellent and stable Eelectricat Properties If the wet wild is s is day,

INTRODUCTION In this experiment, the reaction between magnesium solid and hydrochloric acid will be studied. The rate of reaction and the quantity of reaction will be investigated. The factors that affect each of these will be determined by varying experimental conditions.

4. [Crowl 6-13] Liquid heptane is stored in a 100,000-L storage vessel that is vented directly to air. The heptane is stored at 25°C and latm pressure. The liquid is drained from the storage vessel and all that remains in the vessel is the air saturated with heptane vapor. a) Is the vapor in the storage vessel flammable? b) What is the TNT equivalent for the vapor remaining in the vessel? c) If the vapor explodes, what is the overpressure 50m from the vessel? d) What damage can be expected at 50m?

- A compound was analysed and found to contain40 g C, 53.3 g 0, and 6.7 g H. What is the empirical formula of the compound? (Atomic mass: C = 12.01 g/mol, O =16 g/mol, H = 1 g/mol)

1) a) A bare Si wafer is oxidized in dry O₂ at 1000 °C. The desired final thickness is 40 nm. i) Find the time required to perform the oxidation, ignoring rapid growth. ii) Find the time required to perform the oxidation, taking rapid growth into account. Do not use oxide growth curves. b) A <100> silicon wafer is oxidised using the following sequence i) 40 mins @ 1000°C in dry O₂. ii) 60 mins @ 1000°C in steam. iii) Etch 0.3 microns of oxide. iv) 20 mins @ 1100°C in dry O₂. Use growth curves to calculate the oxide thickness after each step. Nitride- Silicon Wafer Oxidation: Pad Oxide Oxide Nitride removal: "Bird's beak" [10 1/3 marks] [10 marks] Figure 1. LOCOS process c) The diagram above, Figure 1, shows a fully recessed LOCOS (Local Oxidation of Silicon) process. Explain, with reference to the diagram, how the process is used to produce areas of oxide on a wafer without a subsequent lithography and etch step. [5 marks] d) Discuss five of the features of SiO₂ which account for its widespread use in microelectronics. [5 marks]/n

Add or subtract the following measurements. Be sure each answer you enter contains the correct number of significant digits. 18.877 g 1.40 g 6.92 g 1.3 g 18.770 g + 0.77 g = = = g g 0 X S

Classify each reaction and give the name of all the chemical formula involved for each number. 1. Na2CO3(s) + SiO2(s) → Na2SiO3(l) + CO2(g) 2. 2 Mg(NO3)2(s) → 2 Mg(NO2)2(s) + O2(g) 3. 3 HNO2(aq) → 2 NO(g) + NO3-(aq) + H3O+(aq) 4. BaCO3(s) → BaO(s) + CO2(g) 5. 2 Eu2+(aq) + 2 H+(aq) → 2 Eu3+(aq) + H2(g) 6. [Ag(NH3)2]+(aq) + 2 CN-(aq) → [Ag(CN)2]-(aq) + 2 NH3(aq) 7. MgO(s) + 2 HCl(aq) → MgCl2(aq) + H2O(l) 8. CaO(s) + SO2(g) → CaSO3(s) 9. 2 NO(g) + O2(g) → 2 NO2(g) 10. N2(g) + 2 O2(g) → 2 NO2(g)

1. The SA Water desalination plant in Lonsdale was officially opened in 2013 to assist with fresh water supply during the 2000s drought. As we are no longer drought- stricken in South Australia, the plant currently operates at 10% of its 300 megalitre/day capacity. The sea water feeding the desalination plant along the coast of Lonsdale has a salinity value of 35 grams/litre. The brine (salty water) output from desalination plant is has a salinity of 75 grams/litre. The density of sea water can be assumed to be 1020kg/m3 and the density of the brine as 1050kg/m3. a. Determine the mass flow rates of the brine and pure water streams leaving the desalination plant in kg/hr. [6.125 * 105 kg/hr] b. If the salinity meter used to determine the salt content in the water is accurate to the nearest 1g/L and has a precision level of ±5%, determine the uncertainty in the flow rate of the brine. [Assuming independent ±4.4*104 kg/hr]