Answer:
In the third tube, the concentration is 0.16 ug/mL
Explanation:
In the first step, the solution is diluted by 5. Then, the concentration will be
20 ug/mL / 5 = 4 ug/mL
Then, in the second step this 4 ug / ml solution is diluted by a factor of five again:
4 ug /ml / 5 = 0.8 ug/mL
This solution is then diluted again by 5 and the concentration in the third tube will be then:
0.8 ug/mL / 5 = <u>0.16 ug/mL </u>
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Another way to calculate this is to divide the original concentration by the dilution factor ( 5 in this case) elevated to the number of dilutions. In this case:
Concentration in the third tube = 20 ug/mL / 5³ = 0.16 ug/mL
<span>: The empirical formula for the compound is C3H60 (see below)
CO2 is the only product containing C,
C produced = 145.0 mg CO2 x (1 g / 1000 mg) x (1 mole CO2 / 44.0 g CO2) x (1 mole C / 1 mole CO2) = 0.00330 moles C.
H2O is the only product containing H,
H produced = 59.38 mg H2O x (1 g / 1000 mg) x (1 mole H2O / 18.0 g H2O) x (2 moles H / 1 mole H2O) = 0.00660 moles H.
Oxygen is in both and the unknown reacts with oxygen(in the air)
0.00330 moles C x (12.0 g C / 1 mole C) = 0.0396 g C = 39.6 mg C
0.00660 moles H x (1.01 g H / 1 mole H) = 0.00667 g H = 6.7 mg H
Because the unknown weighed 63.8 mg and consists off justC, H, and O, then
mass O = g unknown - g C - g H = 63.8 mg - 39.6 mg - 6.7 mg = 17.5 mg = 0.0175 g
0.0175 g O x (1 mole O / 16.0 g O) = 0.00109 moles O
The mole ratio of C:H:O is:
C = 0.00330
H = 0.00660
O = 0.00109
Divide by the smallest you get:
C = 0.00330 / 0.00109 = 3.03
H = 0.00660 / 0.00109 = 6.06
O = 0.00109 / 0.00109 = 1.00</span>
Answer:
Final pressure =P₂ = 15.13 psi
Explanation:
Given data:
Initial volume = 0.250 L
Initial pressure = 14.7 psi
Initial temperature = -80.0°C (-80.0 +273 = 193 K)
Final volume = 0.375 L
Final temperature = 25.0°C (25+273 =298 k)
Final pressure = ?
Solution:
P₁V₁/T₁ = P₂V₂/T₂
P₁ = Initial pressure
V₁ = Initial volume
T₁ = Initial temperature
P₂ = Final pressure
V₂ = Final volume
T₂ = Final temperature
Now we will put the values in formula.
P₂ = P₁V₁ T₂/ T₁ V₂
P₂ = 14.7 psi × 0.250 L × 298 K / 193 K × 0.375 L
P₂ = 1095.15 psi .L. K / 72.375 K.L
P₂ = 15.13 psi
