Answer:
79.7%
Explanation:
Percent yield of reaction is defined as the ratio between theoretical yield of a reaction and actual yield obtained.
In the problem, theoretical yield are 6 moles of KNO₃ and actual yield are 4.78 moles. Thus, percent yield is:
4.78 mol / 6 mol × 100 =<em> 79.7%</em>
Answer:
Probably it was ment to illustrate how significant and indivisible, being very small, atoms are and how each of them under normal conditions of presure and temperature find their own place eventually
This is a simple algebraic problem, specifically for the mixture type of problem. Let x be the mass of 40% solution and y be the mass of 70% solution. The first equation would then be:
x + y = 20 --> eqn 1
The second equation would be the mass balance shown below:
(x)(0.40) + y(0.70) = 20(0.52) --> eqn 2
Rearranging eqn 1,
x = 20 - y
Substitute this to eqn 2:
(20 - y)(0.40) + y(0.70) = 20(0.52)
Solve for y,
y = 8 grams
Finally, solve for x.
x = 20 - 8 = 12 grams
<em>Therefore, Serena needs 12 grams of the 40% solution and 8 grams of the 70% solution.</em>
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.
The answer is B
hope this helps!!! have a great day
