Is acetic acid flammable?

A sample of an unknown gas takes 222 s to diffuse through a porous plug at a given temperature. At the same temperature, N2(g) t

gulaghasi [49]

Answer:

$\large \boxed{\text{45.1 g/mol}}$

Explanation:

Graham’s Law applies to the diffusion of gases:

The rate of diffusion (r) of a gas is inversely proportional to the square root of its molar mass (M).

$r \propto \dfrac{1}{\sqrt{M}}$

If you have two gases, the ratio of their rates of diffusion is

$\dfrac{r_{2}}{r_{1}} = \sqrt{\dfrac{M_{1}}{M_{2}}}$

The time for diffusion is inversely proportional to the rate.

$\dfrac{t_{2}}{t_{1}} = \sqrt{\dfrac{M_{2}}{M_{1}}}$

Data:

t₂ = 222 s

t₁ = 175 s

M₁ = 28.01

Calculation :

$\begin{array}{rcl}\dfrac{222}{175} & = & \sqrt{\dfrac{M_{2}}{28.01}}\\\\1.269 & = & \sqrt{\dfrac{M_{2}}{28.01}}\\\\1.609 & = & \dfrac{M_{2}}{28.01}\\\\M_{2} & = & 1.609 \times 28.01\\ & = & \textbf{45.1 g/mol}\\\end{array}\\\text{The molar mass of the unknown gas is $\large \boxed{\textbf{45.1 g/mol}}$}$

3 0

3 years ago

Calculate the pH in titration of a weak acid: What is the pH in titration of formic acid (HCHO2, 0.200 M, 100.0 mL) after the ad

ki77a [65]

Answer:

pH = 12.61

Explanation:

First of all, we determine, the milimoles of base:

0.120 M = mmoles / 300 mL

mmoles = 300 mL . 0120 M = 36 mmoles

Now, we determine the milimoles of acid:

0.200 M = mmoles / 100 mL

mmoles = 100 mL . 0.200M = 20 mmoles

This is the neutralization:

HCOOH + OH⁻ ⇄ HCOO⁻ + H₂O

20 mmol 36 mmol 20 mmol

16 mmol

We have an excess of OH⁻, the ones from the NaOH and the ones that formed the salt NaHCOO, because this salt has this hydrolisis:

NaHCOO → Na⁺ + HCOO⁻

HCOO⁻ + H₂O ⇄ HCOOH + OH⁻ Kb → Kw / Ka = 5.55×10⁻¹¹

These contribution of OH⁻ to the solution is insignificant because the Kb is very small

So: [OH⁻] = 16 mmol / 400 mL → 0.04 M

- log [OH⁻] = pOH → 1.39

pH = 14 - pOH → 12.61

6 0

3 years ago

Describe an experience you've had making or building something where the amount of each ingredient or building block came in fix

nignag [31]

<span>Baking a cake is an example of making something where the ingredients must be in fixed ratios. Recipes call for specific ratios of ingredients in order to cook properly, and when a recipe for a cake is modified to feed greater or fewer people the ratio remains the same as the original recipe.</span>

4 0

4 years ago

Select which of the following are used to determine the age of the Earth. Select 3.

saveliy_v [14]

Meteorites discovered on earth

7 0

3 years ago

A meteorologist wants to create a visual aid different gases in earths atmosphere which type of chart or graph would best convey

Karolina [17]

Answer:

A pie chart

Explanation:

A pie chart would be the ideal type of chart to create this visual aid. A pie chart is simpler visually and easily understood. It can show data as portions or percentages of a whole. Since what they want is to present the different gases found in Earth's atmosphere, they can show what percentage of the different gases make up the atmosphere.

It is simpler because the size of each portion or "slice" of the pie chart itself can reveal a lot about the data without even reading the numbers.

4 0

3 years ago

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