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3 years ago

A solution of H2SO4 (90.08 g/mol) has 785.6 g of H2SO4 and 359 g of H2O. What is the molal concentration (molality)?

Chemistry

1 answer:

tekilochka [14]3 years ago

8 0

The molality of H₂SO₄ solution is 24.2 m.

<u>Explanation:</u>

We need to find the molality of sulfuric acid.

Mass of sulfuric acid = 785.6 g

Mass of water = 359 g

We have to find the moles of H₂SO₄ by using its mass and molar mass as,

Moles of H₂SO₄ = $$\frac{785.6g}{90.08 g/mol}$

= 8.7 moles

Mass of the solution in kg = $$\frac{359}{1000}$ = 0.359 kg

Molality = $$\frac{moles}{solvent (kg)}$

= $$\frac{8.7 mol }{0.359 kg}\\$

= 24.2 m

So molality of the H₂SO₄ solution is 24.2 m.

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Answer:

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3 years ago

Assume you mixed 5 µl of your cod fish homogenate with 195 µl working solution. The fluorometer displays a measurement of 12.2 µ

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3 years ago

The gas-phase reaction follows an elementary rate law and is to be carried out first in a PFR and then in a separate experiment

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Answer:

The activation energy is $=8.1\,kcal\,mol^{-1}$

Explanation:

The gas phase reaction is as follows.

$A \rightarrow B+C$

The rate law of the reaction is as follows.

$-r_{A}=kC_{A}$

The reaction is carried out first in the plug flow reactor with feed as pure reactant.

From the given,

Volume "V" = $10dm^{3}$

Temperature "T" = 300 K

Volumetric flow rate of the reaction $v_{o}=5dm^{3}s$

Conversion of the reaction "X" = 0.8

The rate constant of the reaction can be calculate by the following formua.

$V= \frac{v_{0}}{k}[(1+\epsilon )ln(\frac{1}{1-X}-\epsilon X)]$

Rearrange the formula is as follows.

$k= \frac{v_{0}}{V}[(1+\epsilon )ln(\frac{1}{1-X}-\epsilon X)]............(1)$

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$\epsilon =y_{A_{o}}\delta$

$\delta$ = change in total number of moles per mole of A reacte.

$=1(2-1)=1$

Substitute the all given values in equation (1)

$k=\frac{5m^{3}/s}{10dm^{3}}[(1+1)ln \frac{1}{1-0.8}-1 \times 0.8] = 1.2s^{-1}$

Therefore, the rate constant in case of the plug flow reacor at 300K is $1.2s^{-1}$

The rate constant in case of the CSTR can be calculated by using the formula.

$\frac{V}{v_{0}}= \frac{X(1+\epsilon X)}{k(1-X)}.............(2)$

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Hence, the mole fraction of A in feed $y_{A_{o}}$ is 0.5

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$=0.5(2-1)=0.5$

Substitute the all values in formula (2)

$\frac{10dm^{3}}{5dm^{3}}=\frac{0.8(1+0.5(0.8))}{k(1-0.8)}=2.8s^{-1}$

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The activation energy of the reaction can be calculated by using formula

$k(T_{2})=k(T_{1})exp[\frac{E}{R}(\frac{1}{T_{1}}-\frac{1}{T_{2}})]$

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3 years ago

What is the mass of six of these marbles? What is the volume? What is the<br> density?

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Answer:

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Explanation:

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3 years ago

An extra-strength aspirin contains 0.500 g of aspirin. how many grains is this? (1grain=64.8mg)

Snowcat [4.5K]

By unit conversion, the aspirin contains 7.72 grains.

We need to know about unit conversion to solve this problem. The unit conversion can be used to convert a unit to another unit. It can be defined as

a = xb

where a is unit a, b is unit b and x is the constant of conversion.

From the question above, we know that

m = 0.5 gram

unit conversion

(1 grain = 64.8 mg)

Convert the unit conversion to 1 mg

1 grain = 64.8 mg

1/64.8 grain = 64.8/64.8 mg

1 mg = 1/64.8 grain

Convert the aspirin mass to grain

m = 0.500 g

m = 0.5 x 10³ mg

m = 0.5 x 10³ x 1/64.8 grain

m = 7.72 grain

Find more on unit conversion at: brainly.com/question/4158962

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1 year ago