Answer Happy

1. When using a crucible and lid, why must the crucible and lid be inspected for cracks before using? 2. What is meant by "firing the crucible"? Why must we "fire" the crucible before using it? 3. A 1.30 g sample of titanium chemically combines with chlorine gas to form 5.16 g of titanium chloride. (a) What is the empirical formula of titanium chloride? (b) What is the percent by mass of titanium and the percent by mass of chloride in the sample? 4. A 0.500 g sample of tin foil reacted with oxygen to give 0.635 g of product. (a) What is the empirical formula of the tin oxide? (b) What is the percent by mass of tin and the percent by mass of oxygen in the sample? 5. Epsom salt is commonly purchased in the pharmacy for a variety of uses, anti-inflammatory, laxative, and cosmetic. Epsom salt is a hydrated salt of magnesium sulfate. If 2.000 g of Epsom salt are heated to remove the waters of hydration, 0.977 g of the anhydrous (without water) magnesium sulfate, MgSO4, were obtained. Calculate the number of waters of hydration, and write the chemical formula of the Epsom salt.