1. 64.3 g Na2CO3 was dissolved in water and reacted with an excess of aqueous AlCl3 in a beaker. a. Write the balanced chemical reaction. b. What are all the mole ratios of this problem?c. How much NaCl was formed? 2. 13.6 g of Ethane (C2H6) is allowed to burn in the air to form CO2 and H2O. a. Write the balanced chemical reaction. b. How much oxygen was used up?c. How much water vapor was formed?3.

3. 8.45 g of Aqueous potassium phosphate is reacted with 6.23 g of calcium nitrate. a. Write the balanced chemical equation. b. What is the limiting reactant?c. What is the theoretical yield of Ca3(PO4)2?d. If 2.42 g of Calcium phosphate is filtered out of the resulting solution, what is the actual yield?e. What is the percent yield of this reaction?f. How much of the excess was left over?4.

4. 5.67 grams of nickel (III) acetate is added to 85.6 mL of a 0.786 M lithium carbonate and allowed to react. a. Write the balanced chemical equation. b. What is the limiting reactant?c. What is the theoretical yield of the Ni2(CO3)3? d. If 3.58 g of nickel (III) carbonate is filtered out of the resulting solution, what is the actual yield?e. What is the percent yield of this reaction?f. How much of the excess was left over?

Please, I want at least ONE or two of these answered with EXPLINATION; I seriously want to learn how to do stoichiometry propely and no study guides have helped.

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.”

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.

c (diamond),

sio2 (quartz)