Chemistry Help Please! Worth a lot of points!
1. Joseph Priestly was the first scientist to be able to prepare pure oxygen gas. He did this by heating mercuric oxide as shown in the reaction below. Answer the question related to the reaction.
2HgO(s) = 2Hg(l) + O2(g)
a.What volume of oxygen gas would be produced at STP through the decomposition of 5.36 grams of HgO? It is not collected over water!
b. What volume of oxygen gas would be produced at 23o and 0.975 atm by the decomposition of 5.36 grams of HgO?
c. What volume of oxygen gas would be collected over water at 23oC and 0.975 atm by the decomposition of 5.36 grams of HgO?
2. How many grams of water will form through the reaction of 550 mL of 2.5 M HCl and an excess amount of Ca(OH)2?
Ca(OH)2(aq) + 2HCl(aq) = CaCl2(aq) + 2H2O(l)
a. How many grams of calcium chloride will form if 250 mL of 2.0 M Ca(OH)2 reacts with 350 mL of 2.5 M HCl? Make sure to determine the limiting reagent!
3. Sam conducted an experiment where he reacted 5.0 grams of magnesium with an excess amount of oxygen gas to form magnesium oxide (MgO). When he conducted this in the lab, he obtained 8.06 grams of magnesium oxide.
a. Write and balance the chemical reaction.
b. Use stoichiometry to predict how many grams of magnesium oxide should form.
c. What is the theoretical yield?
d. What is the actual yield?
e. Calculate the percent yield.
4. Na(s) + Br2(L) = NaBr(s) (not balanced)
b.If 3.05 grams of sodium react with 10.0 grams of diatomic bromine, what is the excess reagent AND how many moles of excess reagent are present after the reaction?
c. How many grams of sodium bromide are formed?