Answer:
The first option.
Explanation:
Warm solvent and stirring promote quick dissolving . Also with small crystals more of the surface is in contact with the solvent than with large crystals.
Start by converting mg to g. There is .001g in every miligram, so there is 0.4g in this sample.
Then find the molar mass of ibuprofen (C13H18O2) which is 206.3g/mol
Then divide grams by the molar mass to get moles of C13H18O2: (0.4g)/(206.3g/mol) = 1.94x10^-3mol C13H18O2
Then multiply moles by Avogadro's number to get molecules: (1.94x10^-3mol)/(6.02x10^23) = 1.17x10^21 molecules of ibuprofen (C13H18O2)
Answer:
Theoretical yield of HI is 512 g.
The percent yield for this reaction is 25%.
Explanation:
Moles of hydrogen gas = 3.0 moles
Moles of iodine gas = 2.0 moles
According to reaction 1 mol of hydrogen gas reacts with 1 mol of iodine gas.
Then 3.0 moles of hydrogen gas reacts with 3.0 mol of iodine gas. But there are 2.0 moles of iodine gas. Hence,Iodine is a limiting reagent. The production of HI will depend upon iodine gas moles.
According to reaction , 1 mol of iodine gas gives 2 moles of HI.
Then 2 moles of iodine gas will give:
of HI
Theoretically we will get 4 moles of HI.
Theoretical yield of HI = 4 mol × 128 g/mol= 512 g
Experimental yield of HI = 1.0 mol
= 1 mol × 128 g/mol= 128 g
The percent yield for this reaction is 25%.
Answer:
Radiocarbon measurement or radiocarbon dating is a method that is used to measure the age of the carbon-based material in living organisms.
Radiocarbon dating is able to estimate age of fossils that are younger than 50,000 years and unable to measure things that died longer than 200,000 years ago because fossils that are too old do not contain carbon or carbon get vanished from too old fossils of organisms. Some of the fossils also get contaminated due to environmental conditions and during teh collection or preservation process.
Thus, radiocarbon measurement is useless when trying to measure most rocks older than 50,000 years.
The shell that is its a sea shell
