Chemistry

Question 1: Rainwater is acidic because CO2 (g) dissolves in the water, creating carbonic acid, H2CO3. If the rainwater is too acidic, it will react with limestone and seashells (which are principally made of calcium carbonate, CaCO3), forming calcium bicarbonate, Ca(HCO3)2

Question 1: Rainwater is acidic because CO2 (g) dissolves in the water,creating carbonic acid, H2CO3. If the rainwater is too acidic,it will react with limestone and seashells (which are principally made of calcium carbonate, CaCO3), forming calcium bicarbonate, Ca(HCO3)2 CO2(g) + H2O (l)H+(aq) +HCO3–(aq) H+(aq) + CaCO3(s)Ca+(aq) + HCO3– (aq) Write the equilibrium expression of the forward and reversed reactions for each of …

Question 1: Rainwater is acidic because CO2 (g) dissolves in the water, creating carbonic acid, H2CO3. If the rainwater is too acidic, it will react with limestone and seashells (which are principally made of calcium carbonate, CaCO3), forming calcium bicarbonate, Ca(HCO3)2 Read More »

7. Some metals change their crystal structure during heating. Name this effect! How can this effect be proven experimentally? Name and describe the experimental procedure and draw the resulting measurement curve! (6 points) Name of the effect: Experimental description:

EXPERT ANSWER Answer: Annealing is the effect due to which metals change their crystal structure during heating. Experimental procedure: The brass samples were heated in an oven at 800 degrees Celsius and then allowed to cool in the oven overnight. The Rockwell Hardness Tester was used to measure the hardness of the brass samples, as …

7. Some metals change their crystal structure during heating. Name this effect! How can this effect be proven experimentally? Name and describe the experimental procedure and draw the resulting measurement curve! (6 points) Name of the effect: Experimental description: Read More »

Chemical Reactions: Molecular Equation: HCl(aq) + NaOH(aq) NaCl(aq) + H20(1) Net Ionic Equation: H*(aq) + OH(aq) → H2O(1) Trial 1 Trial 3 Trial 2 0.1024 25.00 25.00 25.00 Details Molarity of HCl Standard Solution Volume (mL) HCI Standard Solution No. of mmoles HCl = No. of mmoles H* No. of mmoles OH reacted with HCI No. of mmoles NaOH reacted with HCI Final Reading (mL) NaOH Buret Initial Reading (mL) NaOH Buret Volume (mL) NaOH Solution Delivered Molarity of NaOH Average Molarity of NaOH Deviation Standard Deviation Relative Standard Deviation (%) 22.17 0.05 22.15 0.05 22.28 0.10 0.1157 0.1158 0.1154

EXPERT ANSWER

2. The chemical reaction equation for respiration of glucose is: Candida utilis cells convert glucose to CO, and H,O during growth. The cell composition is CH,,00,No.plus 5% ash. Yield of biomass from substrate is 0.5 g g Ammonia is used as nitrogen source. (i) What is the oxygen demand with growth compared to that without? (ii) C. ltilis is also able to grow with ethanol as substrate, producing cells of the same composition as above. On a mass basis, how does the maximum possible biomass yield from ethanol compare with the maximum possible yield from glucose?

EXPERT ANSWER

2) Give the expected products of the reaction of pent-1-ene with the following reagents, paying attention to the expected regioselectivity. (answer 2 of the 4) (a) Br 2 ​ in CCl 4 ​ (b) HBr (c) Br 2 ​ in MeOH (d) ICl in CCl 4 ​ 3) Terpin can be prepared through the hydration of (R) -limonene as shown below. (a) Draw an arrow-pushing mechanism for this transformation. (b) Would you expect tegpin to be optically active? Justify your reasoning. 4) The following reaction is an example of iadolactonisation. Using your knowledge of the addition of halogens to alkenes, propose a mechanism for this transformation. Based upon your mechanism, which diastereoisomer of product (3 or 4 ) is expected? Or

EXPERT ANSWER