Chromium, mass percent

A mixture of chromium and zinc weighing 0.362 g was reacted with an excess of hydrochloric acid. After all the metals in the mixture reacted, 225 mL of dry hydrogen gas was collected at 27°C and 750. torr. Determine the mass percent of Zn in the metal sample. [Zinc reacts with hydrochloric acid to produce zinc chloride and hydrogen gas chromium reacts with hydrochloric acid to produce chromium(III) chloride and hydrogen gas.]... 

For example, suppose a 0.358-g sample of chromium reacts with oxygen to form 0.523 g of the metal oxide. Then the mass percent of chromium is ... 

This compound has the highest ratio of oxygen atoms to chromium atoms and so must have the greatest mass percent of oxygen. 

Q9. Calculate the mass percent of chromium in the mineral chromite (FeCr204). 

Mass Balance Estimates. Based on National Pollutant Discharge Elimination System monitoring reports, the total daily discharge of trace elements into the main stem Willamette River is of the order of 100 pounds per day. Seventy-five percent of the total is zinc with the bulk of the remainder due to chromium and copper. Table 6 identifies industrial and natural sources of trace elements into the Willamette basin. The table indicates that an average of 97 percent of all trace element loading to the basin is natural in origin. The natural component is due to weathering of soil and rocks in the basin and this... 

In a 194.20 g sample, 78.20 g is potassium, 52.00 g is chromium, and 64.00 g is oxygen. Divide each of these masses by the gram molecular mass, and then multiply by 100 to get the percent composition ... 

Which of the following compounds has a greater percent by mass of chromium, K2Cr04 or K2Cr207 ... 

An oxide of chromium is 68.4 percent chromium by mass. The molar mass of the oxide is 152 g/mol. What is the formula of the compound ... 

In a 1-L beaker, 203 mL of 0.307 A7 ammonium chromate was mixed with 137 mL of 0.269 A7chromium(lll) nitrite to produce ammonium nitrite and chromium(lll) chromate. Write the balanced chemical reaction occurring here. If the percent yield of the reaction was 88.0%, what mass of chromium(lll) chromate was isolated ... 

Table 4 gives the debris recovery summary of the IET-1, IET-3, and IET-6 experiments. The results are reported for four basic locations (1) from inside the subcompartment structures, (2) from the Surtsey vessel outside the structures, (3) from the cavity and instrument tunnel chute, and (4) from the crucible. The total molten mass available for dispersal into the vessel is usually about 20 percent greater than the initial iron oxide/aluminum/chromium thermite charge due to the melting of the inner wall of the crucible, vaporization of the fusible brass plug, ablation of concrete in the cavity, and oxidation of metallic debris [Ref. 8]. 

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