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3 years ago

Help please

Chemistry

2 answers:

andrew11 [14]3 years ago

6 0

Answer:

K2Cr2O7

Explanation:

Solubility refers to the amount of substance that dissolves in a given mass or volume of solvent. There are several units of solubility applicable in different areas.

Solubility is dependent on temperature. The solubility curve is a graphical representation of the dependence of solubility on temperature for different chemical species.

If we study the solubility curve closely, we will see that K2Cr2O7 has the highest solubility at 100°C. This means that if the trends continue, this substance will also have the highest solubility at 120°C.

Vedmedyk [2.9K]3 years ago

5 0

Answer: c

Explanation:

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seraphim [82]

Answer: C.

Explanation:

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3 years ago

Read 2 more answers

A 3.96x10^-24 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvet; a blank solution containi

viktelen [127]

Actual question from source:-

A 3.96x10-4 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000 cm cuvette. A blank had an absorbance of 0.029. The absorbance of an unknown solution of compound A was 0.375. Find the concentration of A in the unknown.

Answer:

Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$

Explanation:

According to the Lambert's Beer law:-

$A=\epsilon l c$

Where, A is the absorbance

l is the path length

$\epsilon$ is the molar absorptivity

c is the concentration.

Given that:-

c = $3.96\times 10^{-4}\ M$

Path length = 1.000 cm

Absorbance observed = 0.624

Absorbance blank = 0.029

A = 0.624 - 0.029 = 0.595

So, applying the values in the Lambert Beer's law as shown below:-

$0.595=\epsilon\times 1.000\ cm\times 3.96\times 10^{-4}\ M$

$\epsilon=\frac{0.595}{3.96\times 10^{-4}}\ {Ms}^{-1}=1502.53\ {Ms}^{-1}$

<u>Molar absorptivity of compound A = $1502.53\ {Ms}^{-1}$ </u>

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3 years ago

present day india is in south asia at the northern end of the indian ocean what evidence found in india matches that of other lo

alekssr [168]

Answer:

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Explanation:

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3 years ago

True or false, The atomic number of an element is a whole number that decreases as you read across each row of

torisob [31]

Answer:

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3 years ago

An equimolar mixture of acetone and ethanol is fed to an evacuated vessel and allowedto come to equilibrium at 65°C and 1.00 atm

frutty [35]

The question is incomplete, the table of the question is given below

Answer:

I) xA= 0.34, yA= 0.55

ii) 76.2 mole % vapor

iii) Percentage of vapor volume = 98%

Explanation:

i) xA= 0.34, yA= 0.55

xA= 0.34, yA= 0.55

ii) 0.50 = 0.55 nv + 0.34 nL

Therefore, nV = 0.762 mol vapor and nL = 0.238 mol liquid

This shows 76.2 mole % vapor

iii) ρA= 0.791 g/cm3 and, ρE = 0.789 g/cm3

Therefore, ρ = 0.790 g/cm3

Now, we have:

MA = 58.08 g/mol and ME= 46.07 g/mol

So Ml = (0.34 x 58.08)+[(1 -0.34) x 46.07] = 50.15 g/mol

1 mol liquid = (0.762 mol vapor/0.238 mol liquid) = 3.2 mol vapor

Liquid volume = Vl= [1 mol x (50.15 g/mol)] / (0.790 g/cm3) = 63.48 cm3

Vapour volume = Vv = 3.2 mol x(22400 cm3/mol) x [(65+273)/273] = 88747 cm3

Therefore, percentage of vapour volume = 88747 / (88747+63.48) = 99.9 %

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3 years ago