Answer:
D
Explanation:
When a dilution is made, a volume of the stock solution is collected and then is mixed to the solvent. The total amount of the solute (number of moles or mass), must be equal in the volume of the sample and at the final volume, because of the Lavoiser's law (the matter can't be created nor destructed).
The mass or the number of moles is the concentration (C) multiplied by the volume (V), so, if 1 is the sample of the stock solution, and 2 the diluted solution:
C1*V1 = C2*V2
The final volume of the solution is 10 mL. So, let's identify the volume needed for each stock solution.
Acetaminophen
C1 = 500 ug/L
C2 = 50 ug/L
500*V1 = 50*10
V1 = 1 mL
Dextromethorphan
C1 = 1 mM = 1000 uM
C2 = 20 uM
1000*V1 = 20*10
V1 = 0.2 mL
So, the volume of water needed is the total less the volume of the stocks solutions less the volume of the embryo water:
V = 10 - 1 - 1 - 0.2 = 7.8 mL
Thus, to to the solution, it's necessary to add at 1 mL of the embryo water 1 ml of 500 ug/I acetaminophen and 0.2 ml of 1 mM dextromethorphan, and 7.8 ml of water.
<u>Answer:</u> 0.5 moles of
are produced in the reaction
<u>Explanation:</u>
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
......(1)
Given mass of
= 113.6 g
Molar mass of
= 79.5 g/mol
Plugging values in equation 1:
![\text{Moles of CuO}=\frac{113.6g}{79.5g/mol}=1.43 mol](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20CuO%7D%3D%5Cfrac%7B113.6g%7D%7B79.5g%2Fmol%7D%3D1.43%20mol)
For the given chemical reaction:
![2NH_3+3CuO\rightarrow 3Cu+N_2+3H_2O](https://tex.z-dn.net/?f=2NH_3%2B3CuO%5Crightarrow%203Cu%2BN_2%2B3H_2O)
By the stoichiometry of the reaction:
If 3 moles of
produces 1 mole of ![N_2](https://tex.z-dn.net/?f=N_2)
So, 1.43 moles of
will produce =
of ![N_2](https://tex.z-dn.net/?f=N_2)
Hence, 0.5 moles of
are produced in the reaction
The answer is 100 Pa.
The formula for calculating pressure is :
<u>Pressure = Force ÷ Area</u>
<u />
We are given that :
We also know that :
<u>Force = mass ×g</u>
<u />
So, force will be :
Now, we can finally calculate pressure :
Molar mass of sulfur dioxide (SO2) is 64.066g/mol
molar mass of sulfur is 32.065 g/mol
thus, (32.065/64.066 )x100=50%