How many grams of co are needed to react with an excess of fe2o3 to produce (210.3 g fe) 209.7 g fe? show your work.
co (g) + fe2o3 (s) --> fe (s) + co2 (g)

Alarge marble is dropped in a graduated cylinder with 35ml of water in it. the water level increases to 49ml. what is the volume of the marble

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

Calculate the number of kilojoules to warm 125 g of iron from 23.5°c to 78.0°c.