You are designing a drier that must evaporate 200 lb/h of h2o from sludge by using air. air at 70°f and 50% relative humidity is drawn into the drier and it leaves at 140f and 70% relative humidity. how much volume of dry air needs to be used for this operation?
b. four hundred kg/h of steam from a low pressure turbine at 12.5 atm. and 250 c goes into a feed water heater which preheats the water entering the economizer in a boiler. the steam is comes out of the feed water at 200 c. the water at a flow rate of 500 kg/h enters the feed water heater at 20c. calculate the feed water exit temperature.

How many moles of sulfuric acid (h2so4) are needed to react completely with 6.8 moles of lithium hydroxide (lioh)? 2lioh + h2so4 → li2so4 + 2h2o a. 3.4 mol h2so4b. 6.8 mol h2so4 c. 10.2 mol h2so4 d. 13.6 mol h2so4

Iwould appreciate if someone could me.

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.