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Natalija
1 month ago
5

For each set of dilutions (bleach and mouthwash), the first tube contained a 1:11 dilution (0.5 mL of agent was added to 5.0 mL

of nutrient broth). What was the dilution of the MIC for the mouthwash and the bleach? Hint: You will have to calculate the dilution of each tube 2 – 4.
Chemistry
1 answer:
eduard [2.7K]1 month ago
5 0

Response:

Tube 2: 8.26 * 10^-3; Tube 4: 6.83 * 10^-5

Explanation:

For the MIC test's serial dilutions, each tube should contain an equal volume of nutrient broth: 5.0 mL, while the agent's volume per dilution must also match: 0.5 mL.

The serial dilution process followed was:

  • Tube 1: 0.5/5.5
  • Tube 2: 0.5 mL from tube 1 was diluted with 5.0 mL of broth, resulting in a dilution of tube 2 as (1:11) * (1:11) = (0.5/5.5) * (0.5/5.5) = 1:121 = 8.26 * 10^-3
  • Tube 3: similar calculations yield 1:1331 = 7.51 * 10^-4
  • Tube 4: yields 1:14641 = 6.83 * 10^-5.

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19 days ago
7.744 Liters of nitrogen are contained in a container. Convert this amount to grams.
lorasvet [2795]

Answer:

9.69g

Explanation:

To find the needed outcome, we first need to determine the number of moles of N2 present in 7.744L of the gas.

1 mole of gas takes up 22.4L at STP.

Thus, X moles of nitrogen gas (N2) will fill 7.744L, meaning

X moles of N2 = 7.744/22.4 = 0.346 moles

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1 month ago
Researchers stationed at different areas on a mountain and in a tunnel midway through the mountain boiled water at the same time
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(a) The mass density of a gaseous compound was found to be 1.23 kg m^−3 at 330 K and 20 kPa. What is the molar mass of the compo
castortr0y [3046]

Answer:

La masa molar del compuesto es: 168.82 g/mol

La masa molar del gas es: 16.38 g/mol

Explanation:

(a)

Utilizando la ecuación de gases ideales:

PV=nRT

donde,

P es la presión

V es el volumen

n es el número de moles

T es la temperatura

R es la constante de los gases, cuyo valor es = 0.0821 L.atm/K.mol

Además,

Moles = masa (m) / Masa molar (M)

La densidad (d) = Masa (m) / Volumen (V)

Así, la ecuación de gases ideales se puede expresar como:

PM=dRt

Dado que:-

Presión = 20 kPa = 20000 Pa

La expresión para la conversión de presión en Pascal a presión en atm se muestra a continuación:

P (Pa) = \frac {1}{101325} P (atm)

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(b)

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Presión = 152 Torr

Temperatura = 298 K

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Utilizando la ecuación de gases ideales:

PV=nRT

R = 62.3637\text{torr}mol^{-1}K^{-1}

Aplicando la fórmula:

152 Torr × 0.25 L = n × 62.3637 L.torr/K.mol × 298 K

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La fórmula para calcular los moles se muestra a continuación:

moles = \frac{Mass\ taken}{Molar\ mass}

Así,

0.002045\ moles
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