Chemical Engineering Answers

The compound having lowest oxidation state of iron is;
A. [Fe(CO)5]
B. K2FeO4
C. K4Fe(CN)6
D. K3[Fe(CN)6]

According to postulates of Werner's theory for coordination compounds, which of the following is true?
A. Only primary valencies are non-ionizable
B. Primary and secondary valences are non-ionizable
C. Primary valences are ionizable
D. Secondary valencies are ionizable

Which of the following compounds has sp^2 hybridisation?
A. N2O
B. SO2
C. CO
D. CO2

Choose the incorrect statement from the following:
A. Sigma bond is weaker than pi-bond
B. Pi-bond is weaker than sigma bond
C. Sigma bond can be present alone
D. Pi-bond is present along with sigma bond

Which is the correct order for bond dissociation energy in O2, O2^+, O2^- and O2^2-?
A. O2^- >O2^2- >O2^+ >O2
B. O2 >O2^+ >O2^2- >O2^-
C. O2^- >O2^2- >O2 >O2^+
D. O2^+ >O2 >O2^- >O2^2-

Diamagnetic species are those that have paired electrons. Which of the following are diamagnetic?
A. N2^2- and N2
B. N2 and O2^2-
C. O2^2- and O2
D. O2 and N2^2-

Which of the following have the same bond order?
A. N2 and N2^-
B. N2 and F2^+
C. F2^+ and O2^-
D. N2^- and O2^-

Which of the following is isoelectronic and isostructural?
A. SO3 and CO3^2-
B. CO3^2- and ClO3^-
C. NO3^- and SO3
D. NO3^- and CO3^2-

Liquid methanol is fed to a space heater at a rate of 12.0 L/h and burned with excess air. The product gas is analyzed and the following dry-basis mole percentages are determined: CH3OH = 0.45%, CO2 = 9.03% and CO = 1.81%, density of methanol = 0.792 g/mL
7.1 Write the equations for the process
7.2 Calculate the feed flowrate in mol/h
7.3 Draw and label the material flow diagram which describes the process.
7.4 Calculate the fractional conversion of methanol and the mole fraction of water in the product gas. (Hint- atom balances may assist)
7.5 Calculate the percentage excess air.
7.6 Suppose the combustion products are released directly into a room. List 2 potential problems and 2 measures to control or mitigate these problems.

10 000 kg/hr of a 5% salt in water solution is fed to a desalination unit where the salt is removed from the water to produce fresh water and brine. The desalination water is to contain no more than 500 ppm salt. The brine (salt solution) waste from the process contains 7.25% salt. To optimize the process, some of the brine waste is recycled to the process. After mixing with the fresh feed, the process input contains 6% salt.
6.1 Draw a flow diagram of the process.
6.2 Calculate the flowrates of brine, desalinated water and recycle streams