emphirical formula of a hydride,volume, density,molecular formula.

1. The phosphine that is produced by the reaction of water on calcium phosphide contains an impurity, another gaseous hydride of phosphorus, this hydryde contains 94% phosphorus and 6% hydrogen by mass. Calculate the emphirical formula using the percentages. 2. At 136.5C and a pressure of 760 mmHg, 0.22g of the hydride occupies a volume of 111cubic cm. a.Calculate the volume that the sample would have at STP, assuming that it remains gaseous. b.Calculate the density of the gaseous hydride of phosphurous at STP in g/litre. c.Determine the molecular formula of the hydride of phosphorus.

Is water replaced or

The question arises concerning the density of saltwater: is it because water molecules have moved out of the system, replaced by sodium and chlorine ions, which are heavier, or have the ions moved into the interstices, creating a greater number of particles in the solution? By the gas laws, a cubic meter of gas always maintains a constant number of particles (at equal temp and pressure). Thus, damp air has the same number of particles as dry air, only some particles are lighter (the water). But does this apply to liquids? The molarity and molality measures, without being rigorous, show that there is a difference in a solution of exactly 1 liter and a solution of 1 liter water plus some ... click for more

How do we measure the oxygen that is released from the reduction of Hydrogen peroxide?

If I had a lab where I had Hydrogen peroxide which is reduced in the presence of a catalyst to oxygen and water, how can I measure the amount of oxygen that would be released?

Vapor Density & Ideal Gas Law

Please take a look at the attached lab report on vapor density. Please see the ** items regarding percentage error and calculation of R. I can't figure out how to do the percentage error of my trials and the calculations for the R values are confusing. Thanks for your help. --- Vapor Density and the Ideal Gas Law Lab Conducted: October 10, 2005 Purpose: To use the Ideal Gas Law (PV=nRT) to calculate the molar mass (M) of an unknown real vapor and to determine its identity as either Methanol, Ethanol, Acetone, Pentane or Cyclohexane. Procedure: Boiled 0.5L of water and inserted a flask of an unknown liquid which was covered with a foil cap that had a small hole in it. The unk... click for more

Characteristics of Zinc Oxide

How many litres of 3% (by weight) citric acid is required to dissolve 450 grams of zinc oxide at room temperature? Does the morphology of the zinc oxide effect the answer above? Are there any catalysts that will promote this dissolution?