Chemical Engineering Answers

If 36 000 kg of full cream milk containing 4% fat is to be seperated in a 6 hour period into skim milk with 0.45% fat, what are the flow rates of the two output streams from a continuous centrifuge which accomplishes this seperation? (Start by drawing a flow diagram of the process).

A gas consists of 70% propane (C3H8) and 30% butane (C4H10) by volume. Calculate:
4.1. The stoichiometric amount of air required to burn 100 kmol/hr of feed if air is assumed to be 21% oxygen.
4.2. The percentage excess air present if a dry analysis of the combustion products shows 9% CO2 assuming complete combustion of propane and butane (hint - calculate the nitrogen that is left over from the reached oxygen first and assume the remainder of the exit stream is air).
Reactions:
C3H8 + O2 = CO2 + H2O
C4H10 + O2 = CO2 + H2O

A 15.00 mL sample of solution has 5.8 × 10^-5 g of calcium ion. Calculate the concentration in each of the following units:
3.1 % (m/v)
3.2 ppt
3.3 ppm

It is required to prepare 1250kg of a solution composed of 12 wt. % ethanol and 88 wt. % water. Two solutions are available, the first contains 5 wt. % ethanol, and the second contains 25 wt. % ethanol. How much of each solution are mixed to prepare the desired solution? Check your answer

Water enters a 10.00m^3 tank at a rate of 15.00kg/s and is withdrawn at a rate of 5.00kg/s. The tank is initially half full.

1.1. Is this process continuous, batch or semibatch? Is it transient or steady state?
1.2. Write a mass balance for the process. Identify the terms of the general balance equation present in your equation and state the reason for omitting any terms.
1.3. How long will the tank take to overflow?

Plot a graph of Wavelength against scale readings.
Wavelength - scale readings
396.4 - 11.1
402.6 - 10.1
412.0 - 9.5
414.4 - 9.3
438.8 - 7.9
447.1 - 7.5
471.3 - 6.5
492.2 - 5.8
501.6 - 5.6
504.8 - 5.5
587.5 - 3.7
667.8 - 2.5
706.5 - 2.1.

What is simple harmonic motion. Write down the expression for the velocity and acceleration of such motion at the different positions along its path

Hydrogen spectrum
Wavelength(nm) - scale readings
400 - 9.7
500 - 8.3
600 - 6.0
700 - 2.6.
1. Plot a graph of scale readings against Wavelength
2. What are the Wavelength from the calibration curve for each Wavelengths.
3. What are the amount of energy associated with each of the four Wavelengths

The following readings were obtained in a cooling experiment

Temp( degree). - Time( min)
36.0 - 0
35.2 - 1
34.2 - 2
33.1 - 3
33.5 - 4
32.0 - 5
31.7 - 6
31.5 - 7
31.3 - 8
31.1 - 9
31.0 - 10
Plot a graph of Temp. Against time. From the graph determine the time taken for temperature to fall from 34.0degree to 32.2 degree. Measure the rate of fall of temperature at points 34.0 degree to 31.2 degree

A 251.0 g/hr stream of liquid methyl alcohol, also called methanol, (CH3OH) at 9.00 atm and 28.0°C was held at constant pressure, vaporized and brought to 585.0°C. At what rate must heat be supplied to this system? Assume that methyl alcohol vapor behaves ideally for the temperature range and pressure given.