B - A chemist might determine the fat content in a candy bar.
1) Fatty acids stored in candy bars are (in fact) composed of chemical substances.
2) Choice A makes no sense. This activity belongs in the Biology field. Or if you're an animal activist, you might be interested in undertaking this as a hobby.
3) Choice C is absurd because either you're a Physicist who enjoys an occupation such as this, or you're just plain crazy.
4) Choice D is preposterous because either you're a Meteorologist, or a Geoscientist. Both of which have nothing to do with chemistry.
The balanced chemical reaction is:
CH4 + 2O2 —> CO2 + 2H2O
You need to convert mass to moles (divide by molar mass):
CH4 moles = 5 / 16 = 0.31 mol
O2 moles = 5 / 32 = 0.16 mol
To figure out which reactant is limiting, divide the actual moles by the corresponding coefficient in the reaction:
CH4: 0.31 / 1 = 0.31
O2: 0.16 / 2 = 0.08
O2 is the lower number, so it is the limiting reactant. From the reaction we know it takes 2 moles of O2 to react with each mole of CH4. Therefore, for however many moles of O2 we actually have, half as many moles of CH4 will react. Since we have 0.16 mol of O2, only 0.08 mol of CH4 will react, leaving behind 0.31 - 0.08 = 0.23 mol of CH4.
Now convert back to mass (multiply by molar mass) to find the mass of CH4 remaining:
0.23 x 16 = 3.68g
The closest answer is B.
Dynamic equilibrium of a chemical system is reached when the rate of forward reaction equals to that of the the backward reaction.
N₂ + 3H₂ → 2NH₃
Based on the reaction, Mole ratio of H₂ to N₂ is 3 : 1 [ 1N₂ + 3H₂ → 2NH₃]
∴ if moles of Hydrogen = 6.34 mol
then moles of nitogen = 6.34 mol ÷ 3
= 2.11 moles
∴ 2.11 moles (OPTION 2) of Nitrogen is needed to convert 6.34 moles of Hydrogen into ammonia.
I believe it is false i just finished my chemistry class
