The given statements are from a description of the element lead in a reference handbook. Classify each statement as a qualitativ or quantitative description of lead. Its elemental symbol is Pb. Qualitative It has a density of 11.3 g . cm-³. Its molecular mass is 207.2 amu. Answer Bank It has a melting point of 327.462 °C and a boiling point of 1749 °C. Quantitative It is a bluish-white metal of bright luster. It is very soft, highly malleable, ductile, and a poor conductor of electricity.

Based on this. What was the percentage by mass of water in the sample?

Crime scene investigators keep a wide variety of compounds on hand to help with identifying unknown substances they find in the course of their duties. One such investigator, while reorganizing their shelves, has mixed up several small vials and is unsure about the identity of a certain powder. Elemental analysis of the compound reveals that it is 67.31 % carbon, 6.978% hydrogen, 4.617% nitrogen, and 21.10% oxygen by mass.     Which of the compounds could the powder be? C17H19NO3C17H19NO3 = morphine, analgesic C17H21NO4C17H21NO4 = cocaine, illicit drug C7H5N3O6C7H5N3O6 = 2,4,6-trinitrotoluene (TNT), commonly used explosive C10H15NC10H15N = methamphetamine, stimulant C4H5N2OC4H5N2O = caffeine, stimulant C11H15NO2C11H15NO2 = 3,4-methylenedioxymethamphetamine (MDMA), illicit drug C21H23NO5C21H23NO5 = heroin, illicit drug C3H6NO3C3H6NO3 = hexamethylene triperoxide diamine (HMTD), commonly used explosive

Please answer number 7

2. A student was asked to identify a sample of unknown hydrate. Student was provided with the following experimental data. 3.51 g sample of the hydrate when heated loses water completely and the mass of the residue was found to be 2.22 g. Student was provided with two reference compounds from which student needs to identify the unknown: Cu(NO3)2. 3H2O and Cu(NO3)2. 6H20. Answer the followings. a. Calculate percent water of hydration in the sample. (show your calculations)

What is the volume (in mL) of 0.684 mol of carbon disulfide (MM = 76.13 g/mol) at 20 degrees celsius? The density of carbon disulfide is 1.263 g/mL at 20 degrees celsius. Your answer should have 3 sig figs.

You are given a 15.0 g mixture. You find out that the mixture contains 3.55 g salt, 4.78 g sand and the rest is Iron. According to these data, what is the percent of iron in the mixture? O 55.5% O 6.67% O 44.5% 15,0%

Assuming that the copper and lead are pure, determine the relative amounts of each kind of BB. The density of copper is 8.96 g/cm ^ 3 . The density of lead is 11.4 g/cm ^ 3

Part A: How many atoms of hydrogen does it contain?         Express your answer using four significant figures.   Part B: How many molecules of glucose does it contain?         Express your answer using four significant figures.   Part C: How many moles of glucose does it contain?         Express your answer using four significant figures.   Part D: What is the mass of this sample in grams?         Express your answer using four significant figures.

What is the concentration, in units of grams of dye per liter of solution (g/L), of the dilute dye solution that is produced as follows? Transfer 16.51 mL of the stock solution (6.12 g/L) to a 200.0 mL volumetric flask and dilute to the 200.0 mL line with deionized water. Your answer should be reported to the correct number of significant figures.