1. What is the percent water in calcium chloride dihydrate, CaCl2.2H2O? 2. A 2.50-gram sample of CuSO4 .xH2O is heated, releasing the water. After heating, 1.59 g of the anhydrous salt (CuSO4) remains. What is the empirical formula of the hydrate? 3. A hydrate is found to have 48.8 g MgSO4 and 51.2 g H2O. What is the empirical formula? 4. A 13.52 g sample of Magnesium Sulfate hydrate is heated in a crucible. The crucible contains 6.60 g of anhydrous salt after the second heating. What is the formula of the hydrate? Mg = 24.3; S = 32; O = 16; H = 1. P a g e | 102 Name: Exp. 08 Water of Hydration Post Lab Questions (2 of 2) 5. A 5.00 g sample of NiCl2 .xH2O is heated, driving off 2.28 g of water. What is the empirical formula of the hydrate? Ni = 58; Cl = 35.5; H = 1; O = 16. 6. A 1.74 g sample of K2CO3 hydrate is heated, losing 0.36 g of water. Find the empirical formula. of the hydrate. K = 39; C = 12; O = 16; H = 1. 7. In Part A of the experiment, you reported a % value which is lower than 36.1%. Briefly discuss what may have gone wrong? 8. In Part A of the experiment, you reported a % value which is higher than 36.1%. Briefly discuss what may have gone wrong?

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”

it should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.