Recent activity by EmmettWester

1 answer 36 views

Design a heat exchanger for a specific process in which a 50,000 kg/day of a mixture with a specific heat capacity of 3.5 kJ/kg.K needs to be heated from 20°C to 70°C using a hot stream of 100,000 kg/day of a fluid with a temperature of 150°C. The heat exchanger needs to operate with a heat transfer coefficient of at least 400 W/m2.K and the pressure drop across the heat exchanger should be no more than 0.5 bar. What type of heat exchanger would be most suitable and what are the dimensions required to achieve the desired performance?

asked 1 day ago in Chemical engineering

1 answer 48 views

What is the concentration of iron (Fe) in a sample of river water using spectrophotometry at a wavelength of 510 nm? Given that the absorbance value of the sample at 510 nm is 0.42, and the molar absorptivity of iron (Fe) at that wavelength is 18,000 M^-1 cm^-1.

answered 6 days ago in Analytical Chemistry

1 answer 28 views

Calculate the heat of hydration when 10.0 g of calcium chloride (CaCl2) dissolves in 100 g of water at 25°C. The enthalpy of solution for calcium chloride is -81.5 kJ/mol.

asked Jan 23 in ThermoChemistry

1 answer 6 views

A chemistry student wants to buffer a solution with a pH of 4.5. The student adds 0.1 mol of a weak acid buffer to 0.1 mol of a conjugate base. Taking the pKa value of the buffer into consideration, determine how much stronger an acid in the same buffer system would need to be added to the solution to shift the pH from 4.5 to 4.0, assuming temperature and pressure are constant.

answered Jan 22 in Chemical equilibrium

1 answer 17 views

According to the opponent process theory, what causes the color afterimage effect?

answered Jan 20 in Psychology

1 answer 52 views

Who proposed the Dual Process Model of Coping with Bereavement?

answered Jan 20 in Psychology

1 answer 16 views

Who rejected the reductionist approach to perception?

answered Jan 17 in Psychology

1 answer 35 views

What is the evolutionary mismatch hypothesis?

asked Jan 16 in Psychology

1 answer 23 views

According to the Conservation of Resource theory, what is the main challenge for people undergoing end-of-life issues?

answered Jan 16 in Psychology

1 answer 11 views

What is the difference between inter-sexual and intra-sexual selection?

answered Jan 15 in Psychology

1 answer 30 views

The concept of self-efficacy originated from which psychological theory?

answered Jan 15 in Psychology

1 answer 22 views

What is a key feature of discourse analysis?

asked Jan 15 in Psychology

1 answer 36 views

What is cognitive-behavioural therapy (CBT)?

answered Jan 14 in Psychology

1 answer 17 views

What is linear perspective?

answered Jan 14 in Psychology

1 answer 7 views

Compare and contrast the cross-sectional and sequential research designs.

answered Jan 10 in Psychology

1 answer 49 views

What word do get from the arabic al-qili, meaning “ashes of the saltwort plant from salt marshes”?

asked Jan 8 in Science

1 answer 19 views

What kind of energy positions do electrons occupy during ground state?

answered Jan 7 in Science

1 answer 42 views

What is the term for the arrangement of veins in a leaf?

answered Jan 7 in Science

1 answer 31 views

What does the heat energy affect in the atmosphere?

asked Jan 6 in Science

1 answer 58 views

What do farmers use greenhouses for?

answered Jan 6 in Science

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