The answer to the question is a. Passage I contains a character study, but Passage 2 focuses more on concepts.
for all who were wondering
1) moles = mass/mR
CaCO3 Mr = 40 + 12 + (16×3)
= 52 + 48
= 100
mass = 15
so the moles would be 15 ÷ 100
which is 0.15 moles of CaCO3
2) moles = mass ÷ Mr
Mr of Al2O3 = 27 + (16×3)
= 27 + 48
= 75
mass = 204
so the moles would be 204/75 which is 2.72 moles of Al2O3
Because they are different they all show different traits
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.
Molarity of the resulting solution will be 1.33 M.
<u>Explanation:</u>
First we have to find the number of moles for each of the solution using the formula, moles = molarity × volume
For cup 1 = 1 M ×0.05 L = 0.05 moles
For cup 2 = 2.5 M × 0.05 L= 0.125 moles
For cup 3 = 0.5 M × 0.05 L = 0.025 moles
Total moles = 0.05 + 0.125 + 0.025 = 0.2 moles
We have to find the total volume as, 0.05 + 0.05 + 0.05 = 0.15 L
Now we have to find the molarity as, moles / volume = 0.2 moles/ 0.15 L = 1.33 M
