Chemistry Questions and Answers November 06, 2019

In normal operation, a paper mill generates excess steam at 20 bar and 400 degrees Celsius. It is planned to use this steam as the feed to a turbine to generate electricity for the mill. There are 500 kg/hr of steam available, and it is planned that the exit pressure of the steam will be 2 bar. Assuming the turbine is well insulated, what is the

1. A student dissolves 5.44 g of sodium phosphate hexahydrate to make 250. mL of solution. a. What is the molar concentration of the solution (in M) in terms of (1) sodium phosphate (II) sodium ions (III) phosphate ions b. The student takes 25.00 mL of the solution and adds 75.00 mL of water. What is the concentration of the new solution in terms

Calculate the change in enthalpy for the following specific rxn. Be sure to indicate the correct sign (- or +) for the change in enthalpy: Mg(s) + 2H + (aq) --> Mg 2+ (aq) + H 2 (g) This is for a lab, these are the values I have calculated so far (I'm not sure which ones are relevant to this question): - Heat evolved per mole of Mg: 361380J/mol

What atomic or hybrid orbitals make up the pi bond between C 1 and C 2 in acetylene , C 2 H 2 ? (C 1 is the first carbon in the formula as written.) orbital on C 1 + orbital on C 2 How many bonds does C 1 have in C 2 H 2 ? How many pi bonds does C 1 have?

Given the data in the table below, H rxn for the reaction 2Ag 2 S (s) + O 2 (g) 2Ag 2 O (s) + 2S (s) is ________ kJ. Substance H f(kJ/mol) Ag 2 O (s) -31.0 Ag 2 S (s) -32.6 H 2 S (g) -20.6 H 2 O (l) -286

You have 2.2 mol Xe and 2.0 mol F2 but when you carry out the reaction you end up with only 0.25 mol XEF4. What is the percent yelid of this experiment? Xe(g) + 2F2 (g) = XeF4 (g)

In the laboratory, a quantity of I2 was reacted with excess H2 to give 0.430 moles of HI. It is also known that the percent yield of this reaction was 52.0%. How many moles of I2 reacted? (Hint: Write a balanced equation.)

In this lab you are synthesizing acetylsalicylic acid (ASA) from salicylic acid using acetic anhydride, with phosphoric acid as a catalyst. If the amount of salicylic acid at the start of the reaction was 1.14 g, what is the theoretical yield of ASA in g? Assume acetic anhydride is in excess.

Calculate the pH of a solution made by mixing 25.0 mL of 0.15 M NaOH and 30.0 mL of 0.040 M H 3 PO 4 . (Consider H 3 PO 4 to act as a tri-protic strong acid in this question) Question 3 options: 3.97 11.01 10.37 2.56 11.44

Photons of 182 kj/mol are emitted when electrons in hydrogen fell to the second energy level. determine their original level.

Show all your work and keep significant figures in mind through the problem. Thank you in advance. On the equation below please disregard the : and .

AE2.18 x 1018 J 1 2 nf 2 n,a. Calculate the energy required to ionize a hydrogen atom using the Rydberg Equation above. b. What wavelength of light would be required to ionize a hydrogen atom C. In what region of the electromagnetic spectrum does the light emission occur

Write the mechanism of Reduction of 3-nitroacetophenone by using 1. Tin and Hydrocholoric Acid 2. Sodium Borohydride

H3C. 1. NaBH4 2. H30 Z0 H3C. OH I Z0 IQ H3C 1. Sn HCI 2. NaOH, H2O NH

Plot the total ionization energies of Al n+ as a function of n from n=1 to n=8. Explain the source of discontinuity (if any) in your curve. (Be sure to use a reliable source for the ionization energies and to reference it.) Calculate the Z eff of Al n+ and plot these as a function of n. Are there any conclusions that can be drawn by comparing the