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.
Density is equal to the ratio of mass to the volume.
The mathematical expression is given as:
Arrange the above expression in terms of volume, i.e.
Density of osmium is equal to =
Mass of osmium = 4.80 kg
First, convert the mass in kg to g:
1 kg = 1000 g
Therefore, mass in g = = 4800 g
Put the values,
= .
Hence, volume occupied by osmium =.
Answer:
Molecular Formula = C₆H₆
Explanation:
Molecular formula is calculated by using following formula,
Molecular Formula = n × Empirical Formula ---- (1)
Also, n is given as,
n = Molecular Weight / Empirical Formula Weight
Molecular Weight = 78.0 g.mol⁻¹
Empirical Formula Weight = 12 (C) + 1 (H) = 13 g.mol⁻¹
So,
n = 78.0 g.mol⁻¹ ÷ 13 g.mol⁻¹
n = 6
Putting Empirical Formula and value of "n" in equation 1,
Molecular Formula = 6 × CH
Molecular Formula = C₆H₆