Answer:
D)subscript of C in molecular formula = n x subscript of C in empirical formula
Explanation:
THIS IS THE COMPLETE QUESTION BELOW;
.The empirical formula for a compound is CH2. If n is a whole number, which shows a correct relationship between the molecular formula and the empirical formula? a)<br /><br /> empirical formula mass / molecular mass = n<br /><br /> B) molecular mass = element mass / empirical formula mass ´ 100<br /><br /> c) subscript of H in empirical formula = 2  subscript of H in molecular formula<br /><br /> D) subscript of C in molecular formula = n  subscript of C in empirical formula<br /><br />
An empirical formula can be regarded as "shorten form" of a molecular formula. Instance of this is
A compounds CH4, C2H8, C4H12... with empirical formula of CH4. In this case a constant "n" represent the difference that exist between empirical formula and molecular formula, "n" which is a whole number, molecular formula is the numerator.
Therefore, subscript of C in molecular formula = n x subscript of C in empirical formula
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.
Answer:
A: plants give off water vapor as a waste product as they process energy
Explanation:
Evapotranspiration in plants is defined as the process whereby water is evaporated from its leaves through transpiration during the process of photosynthesis. Different factors like wind, humidity, temperature and availability of water could make it vary.
Comparing all the options, to this definition, the correct answer is Option A.
Solar energy.
This whole process starts with the solar energy. It also involves the sun within the process. Solar energy is radiant light and heat that comes from the sun. So it seems to fit in with the story that was given.
Best of luck on your assignment!
- Emacathy
Answer:
d) C₂H₅O₂
Explanation:
Molecular formula is a whole-number ratio of atoms presents in a molecule. The percentage given is in mass. Thus, we need to convert this percentage to moles using atomic mass of each atom and, in this way, we can solve for the ratio of atoms and molecular formula as follows:
C = 39.33g * (1mol / 12.01g) = 3.275mol
H = 8.269g * (1mol / 1.005g) = 8.228mol
O = 52.40g * (1mol / 16g) = 3.275mol
To obtain the ratio we must divide each amount of moles in the low number of moles (Moles of O or C):
C = 3.275mol / 3.275mol = 1
H = 8.229mol / 3.275mol = 2.5
O = 3.275mol / 3.275mol = 1
Multiplying this ratio in 2 (To obtain the whole-number ratio):
C = 1*2 = 2
H = 2.5*2 = 5
O = 1*2 = 2
The molecular formula is:
C₂H₅O₂
And right answer is:
<h3>d) C₂H₅O₂</h3>
