CHEMICAL ENGINEERING CALCULATIONS PROBLEMS
1. An evaporator is concentrating solutions coming from two different sources. The solutions from
the first source containing 10% NaCl and 10% NaOH flows at the rate of 50kg/min. The other
solution containing 8% NaCl and 12% NaOH flows at the rate of 70kg/min. The two streams
are fed directly to the evaporator. If 50% of the total water is to be evaporated, calculate the
composition and the flow rate of the product.
, 2. The waste acid from a nitrating process contains 30% sulfuric acid, 35% nitric acid, and 35%
water by weight. The acid is to be concentrated to contain 39% sulfuric acid and 42% nitric acid
by addition of concentrated sulfuric acid containing 98% sulfuric acid and concentrated nitric
acid containing 72% nitric acid (wt). Calculate the quantities of three acids to be mixed to get
1000kg of desired mixed acid.
1. An evaporator is concentrating solutions coming from two different sources. The solutions from
the first source containing 10% NaCl and 10% NaOH flows at the rate of 50kg/min. The other
solution containing 8% NaCl and 12% NaOH flows at the rate of 70kg/min. The two streams
are fed directly to the evaporator. If 50% of the total water is to be evaporated, calculate the
composition and the flow rate of the product.
, 2. The waste acid from a nitrating process contains 30% sulfuric acid, 35% nitric acid, and 35%
water by weight. The acid is to be concentrated to contain 39% sulfuric acid and 42% nitric acid
by addition of concentrated sulfuric acid containing 98% sulfuric acid and concentrated nitric
acid containing 72% nitric acid (wt). Calculate the quantities of three acids to be mixed to get
1000kg of desired mixed acid.
