It is often possible to change a hydrate into an anhydrous compound by heating it to drive off the water (dehydration). A 45.21 gram sample of a hydrate of Ca(NO3)2 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 31.41 grams of the anhydrous compound remained. What is the formula of the hydrate?

How many atoms (total) are present in a 3.45 x10-2 m3 sample of Al2O3, which has a density of 3.95 g/cm3?

White sand is made of silica (silicon dioxide, or SiO2), which has a density of 2.20 g/cm3. How many silicon atoms are in a spherical grain of sand 0.385 mm in diameter?

A student is running an experiment in which 67.2 grams of CaSeO4 is needed, but the only jar of reagent in the lab is labelled calcium selenate dihydrate. How many grams of the hydrate must the student weigh out in order to get the desired amount of the anhydrous compound?

Dolomite, a type of rock found in some petroleum reservoirs, is a mixture of CaCO3 and MgCO3. If the mass percent of magnesium in a sample of dolomite is 13.2%, what is the mass percent of calcium in this sample?

13.0 g of titanium reacted with 60.0 g of bromine. In this reaction, assuming 100% yield, 69.0 g of titanium(IV) bromide were produced and 4.01 g of titanium were left after the reaction. Which reactant was the limiting reactant? Which reactant was the excess reactant? Explain your reasoning using complete sentences.

A certain organic compound has the formula C9H11O3. A sample of this compound weighs 3.4 grams. Calculate the number of hydrogen atoms contained in this sample.

On another planet, the isotopes of titanium have the given natural abundances. Abundance Mass (u) Isotope 46Tİ 73.100% 45.95263 48Ti 19.500% 47.94795 50TI 7.400% 49.94479 What is the average atomic mass of titanium on that planet? average atomic mass = * TOOLS х10

A 56.4 g sample of a compound with a molecular mass of210 u was found to be composed of 12.35 g of sodium 25.77 g of carbon, 1.07 g of hydrogen, and an unknown mass of oxygen. What is the molecular formula for this compound?  A chemist analyzed an unknown compound and determined that it was composed of 2.2 percent hydrogen, 26.7 percent carbon, and 71.1 percent oxygen. What is the empirical formula for this compound?  Acetone is a liquid solvent that works well as a nail polish remover. Acetone contains 62.0 percent carbon, lOA percent hydrogen, and 27.5 percent oxygen.  The molecular mass of acetone is 58.1 u. What is the molecular formula for acetone?

Ammonium perchlorate (NH4C104) is the solid rocket fuel that was used by the U.S. Space Shuttle and is used in the Space Launch System (SLS) of the Artemis rocket. It reacts with itself to produce nitrogen gas (N₂), chlorine gas (C1₂), oxygen gas (O₂), water (H₂O), and a great deal of energy. What mass of oxygen gas is produced by the reaction of 9.70 g of ammonium perchlorate? Round your answer to 3 significant digits. g x10 X