1) Calculate the density of NO2 gas at 0.970 atm and 33C degree.
2) Calculate the molar mass of a gas if 2.50g occupies 0.885L at 685 torr and 33C degree.
3) Calcium hydride,CaH2 , reacts with water to form hydrogen gas:
This reaction is sometimes used to inflate life rafts, weather balloons, and the like, where a simple, compact means of generating H2 is desired.
How many grams of CaH2 are needed to generate 54.5L of H2 gas if the pressure of H2 is 813 torr at 21 C degree?
4) The metabolic oxidation of glucose,C6H12O6 , in our bodies produces CO2, which is expelled from our lungs as a gas:
Calculate the volume of dry CO2 produced at body temperature (37 C degree) and 0.980 atm when 24.0 g of glucose is consumed in this reaction.
Provides steps necessary to calculate the density, molar mass and stoichiometry.
Percent Mass and Stoichiometry
1) You are the science officer on the Starship Enterprise. The ship is circling a new planet. The away team comes back with some rocks and minerals. Some of the minerals contain iron and you want to determine the amount of iron in the sample.
You take 9.000 g of this mineral and treat it with excess bromine (bromine reacts with iron metal to produce iron(III) bromide, which is soluble in water). The solution containing the iron(III) bromide and bromine is then treated with excess silver nitrate. The mass of the silver bromide obtained is found to be 46.34 g. What is the percent of iron in the mineral sample?
2) A common laboratory experiment for introductory chemistry courses involves the analysis of a mixture of BaCl2 and BaCl2.2H2O. You are given a white powder that is a mixture of these compounds and are asked to determine the weight percent of each.
You find that 1.392 g of the mixture has a mass of 1.157 g after heating it to drive off
all of the water present.
(A) What is the weight percent of water in the mixture?
(B) What is the weight percent of BaCl2 in the mixture?
(C) What is the weight percent of Ba in the mixture?
3) If a bottle of wine is not kept under appropriate conditions, the ethanol (C2 H5 OH) is oxidized to a limited extent (it turns to acetic acid) and the wine becomes very sour and is no longer drinkable. This can be expressed by the following reaction.
C2 H5 OH + O2--> C2 H4 O2 (Unbalanced)
If the wine contains 15% by mass ethanol (assume the only other ingredient in the wine is water), how many moles of acetic acid are produced in a liter of this wine.
The density of the wine is 1.010 g/mL. Assume that all the ethanol is converted to acetic acid. The molar masses of C, H, and O are 12.011, 1.00794, and 15.9994 g/mole,respectively.