What is 2648 to two significant figures answers

Problem #19: Calculate the freezing point of a solution of 5.00 g of diphenyl C 12H 10 and 7.50 g of naphthalene, C 10H 8 dissolved in 200.0 g of benzene (fp = 5.5 вЊ) Express your answer using two significant figures. Calculate the molar mass of the unknown compound. Problem #18: An aqueous solution containing 34.3 g of an unknown molecular (nonelectrolyte) compound in 160.0 g of water was found to have a freezing point of в€’1.3 вЊ. Calculate the molecular weight for the unknown. When 0.680 g of an unknown are added to the 10.180 g of benzophenone the resulting solution is found to freeze at 42.6 вЊ. Problem #17: A 10.180 g sample of benzophenone is found to freeze at 46.8 вЊ. Determine the molar mass & molecular formula of the compound.ДЎ.04 вЊ = (1) (5.12 вЊ kg molВЇ 1) (x / 0.301 kg) The freezing point of the solution is 1.04 вЊ below that of pure benzene. Problem #16: A 7.85 g sample of a compound with the empirical formula C 5H 4 is dissolved in 301 g of benzene. Prior to coming across this problem and adding it to my web site, the ChemTeam did not know that caffeine dimerizes. The fact that we got exactly double that value shows that caffeine dimerizes in solution and that the van 't Hoff factor should be 0.5 for caffeine. What is the molar mass of caffeine?ДЈ.07 вЊ = (1) (39.7 вЊ kg/mol) (x / 0.0100 kg)ДЇrom other sources, we know the molar mass of caffeine to be 194 g/mol. mg sample of caffeine was dissolved in 10.0 g of camphor (K f = 39.7 вЊ/m), decreasing the freezing point of camphor by 3.07 вЊ. Problem #14: What is the freezing point of a solution of ethyl alcohol, that contains 20.0 g of the solute (C 2H 5OH), dissolved in 590.0 g of water? Problem #13: What is the molar mass of 35.0 g of an unknown substance that depresses the freezing point of 0.350 kg of water 0.50 вЊ? K f for water is 1.86 вЊ/m.Д .50 вЊ = (1) (1.86 вЊ kg molВЇ 1) (x / 0.350 kg) Such values can be easily looked up in standard reference materials. Note that the freezing point constant is not provided. What s the approximate molar mass of lauryl alcohol?ДЎ.344 вЊ = (1) (5.12 вЊ kg molВЇ 1) (x / 0.100 kg) A solution of 5.00 g of lauryl alcohol in 0.100 kg of benzene freezes at 4.1 вЊ.

Problem #12: Lauryl alcohol is obtained from coconut oil and is used to make detergents. What is the molar mass of the unknown compound?Дў) Determine how many moles of the compound dissolved:ДЎ.674 вЊ = (1) (5.12 вЊ kg molВЇ 1) (x / 0.500 kg) The freezing point of pure benzene is 5.444 вЊ and the K f for benzene is 5.12 вЊ/m. Problem #11: When 20.0 grams of an unknown nonelectrolyte compound are dissolved in 500.0 grams of benzene, the freezing point of the resulting solution is 3.77 вЊ. It should also be noted that the the most humiliating defeat in America's recent history was the attack on Pearl Harbor, which was conducted from Japanese aircraft carriers.ChemTeam: Freezing Point Depression Problems #11-25 Freezing Point Depression

With the end of the Cold War, Russia has little need for naval power and Ukraine (former USSR) recently sold a partially completed Soviet aircraft carrier to China. Centralized planning also allowed convoys of ships to have military escorts such as those to Cuba. The Soviet Union did build aircraft carriers, but on a much more limited scale than the USA.Д¬ommunism prevented the Soviet Union from trading as much as the US, since it believed in centralized economies. Nuclear Powered Icebreakers were more important to the Soviet Union (and now Russia) because no other ships (neither aircraft carriers nor tankers) can survive the ice of the Arctic Ocean, which is where much of Russia's oil resources are located. However carriers are also much more vulnerable. They are much more reliable than dictators etc. The US has good reason to believe that it cannot rely on many of its fickle 'allies.' Therefore the US needs another method of projecting military power.

Sometimes the US even gave weapons to bad people (Saddam Hussein, the Taliban of Afghanistan, etc.) to counter the spread of communism or guard its economic interests. The USA believed in projecting military power to guard its economic interests, which included containing the spread of communism ( domino theory). The Soviet Union believed in spreading Communism (an ideology) through giving communist revolutionaries weapons such as guns, tanks, and planes.

What is 2648 to two significant figures answers