) The Einstein equation E=mc2 shows that 1.0g of matteris the equivalent of 2.1 X 1010 kcal. When 2.0 g ofhydrogen reacts with 16 g of oxygen to form 18 g of water, 68 kcalof heat energy is given up. This quantity of energy is attributed to what loss of mass in the reaction system?
2) Methanol also called methy alcohol, is the simplest alcohol. Itis used as a fuel in race cars and is a potential replacement forgasoline. Methanol can be manufactured by combination of gaseouscarborn monoxide and hydrogen. Suppose 68.5 kg of CO (g) is reactedwith 8.60 kg hydrogen gas. Calculate the theoretical yield of methanol. If 3.57 X 104 grams methanol is actuallyproduced what is the percent yield of methanol?
3) A compound consists of 93.75% carbon and 6.25% hydrogen. Thesubstance dissolves in benzene, and 6.14 g of it lowers thefreezing point of 100 g of benzene 2.45 oC. A) What isthe emipirical formula of the compound? B) What is its molecularweight? C)What is its molecular formula?
4) A. Is it geometrically possible for the four hydrogen atomsattached to the end carbon atoms in the 1, 3-butadiene molecule tolie in the same plane? B)If carbon-hydrogen bonds on adjacentsingly bonded carbon atoms tend to repel each other, would it belikely for all six hydrogen atoms to lie in the same plane? C) Ifthey do, what is their relation to the plane of the carbonatoms?
5) A compound consists of 60.0% carbon, 26.7% oxygen, and 13.3 %hydrogen. Its molecular weight is 60. What are the possiblestructures for molecules of this chemical compound?
6) Nitrogen gas can be prepared by passing gaseous ammonia oversolid copper (II) oxide at high temperatures. The other products ofthe reaction are solid copper and water vapor. If a samplecontaining 18.1 g of NH3 is reacted with 90.4 g of CuO,which is the limiting reactant? How many grams of N2 will be formed?