Our blood which is made up of different types of cells is classified as what level of organization? *

Calculate the feed ratio of adipic acid and hexamethylene diamine that should be employed to obtain a polyamide of approximately

artcher [175]

Answer:

r= 0.9949 (For 15,000)

r=0.995 (For 19,000)

Explanation:

We know that

Molecular weight of hexamethylene diamine = 116.21 g/mol

Molecular weight of adipic acid = 146.14 g/mol

Molecular weight of water = 18.016 g/mol

As we know that when adipic acid and hexamethylene diamine react then nylon 6, 6 comes out as the final product and release 2 molecule of water.

So

$M_{repeat}=146.14+166.21-2\times 18.106\ g/mol$

$M_{repeat}=226.32\ g/mol$

So

Mo= 226.32/2 =113.16 g/mol

$M_n=X_nM_o$

Given that

Mn= 15,000 g/mol

So

15,000 = Xn x 113.16

Xn = 132.55

Now by using Carothers equation we know that

$X_n=\dfrac{1+r}{1+r-2rp}$

$132.55=\dfrac{1+r}{1+r-2\times 0.99r}$

By calculating we get

r= 0.9949

For 19,000

19,000 = Xn x 113.16

Xn = 167.99

By calculating in same process given above we get

r=0.995

3 0

3 years ago

A manganese electrode was oxidized electrically. If the mass of the electrode decreased by 225 mg during the passage of 1580 cou

qwelly [4]

Answer:

<u>Oxidation state of Mn = +4</u>

Explanation:

Atomic mass of Mn = 55g/mol

From Faraday's law of electrolysis,

Electrochemical equivalent = $\frac{mass}{charge}$

i.e Z = $\frac{m}{Q}$ = $\frac{0.225g}{1580C}$ = 0.0001424 g/C

But Equivalent weight, E = atomic mass ÷ valency = Z × 96,485

⇒ $\frac{55}{valency}$ = 0.0001424 × 96,485

<u>∴ Valency of Mn = +4</u>

8 0

3 years ago

Which action would speed up a chemical reaction in aqueous solution?

Vedmedyk [2.9K]

Adding more powdered reactants

5 0

3 years ago

Read 2 more answers

A piece of high-density Styrofoam measuring 24.0 cm by 36.0 cm by 5.0 cm floats when placed in a tub of water. When a 1.5 kg boo

zheka24 [161]

Explanation:

The given data is as follows.

Width of Styrofoam = 24.0 cm

Length of Styrofoam = 36.0 cm

Height of Styrofoam = 5.0 cm

Therefore, volume of the Styrofoam will be calculated as follows.

Volume = length × width × height

= (36.0 × 24.0 × 5.0) $cm^{3}$

= 4320 $cm^{3}$

or, = $4.32 \times 10^{3} cm^{3}$

As Styrofoam partially sinks at 3.0 cm and total height of Styrofoam is 5.0 cm. Hence, height of Styrofoam above the water is (5.0 - 3 cm) = 2 cm.

So, volume of water displaced is as follows.

24.0 cm × 36.0 cm × 2.0 cm

= $1.73 \times 10^{3} cm^{3}$

Hence, mass of displaced water is as follows.

mass = density × volume

= $1.00 g/cm^{3} \times 1.73 \times 10^{3} cm^{3}$

= $1.73 \times 10^{3} g$

Since, book is placed on the Styrofoam. Therefore, mass of water displaced is also equal to the following.

Mass of water displaced = mass of book + mass of Styrofoam

$1.73 \times 10^{3} g$ = 1500 g + mass of Styrofoam

(1730 - 1500) g = mass of Styrofoam

mass of Styrofoam = 230 g

Therefore, calculate the density of Styrofoam as follows.

Density = $\frac{mass}{volume}$

= $\frac{230}{4.32 \times 10^{3} cm^{3}}$

= $53.24 \times 10^{-3} g cm^{-3}$

Thus, we can conclude that the density of Styrofoam is $53.24 \times 10^{-3} g cm^{-3}$ .

4 0

3 years ago

Part A Find ΔS∘ for the reaction between nitrogen gas and hydrogen gas to form ammonia: 12N2(g)+32H2(g)→NH3(g) Express your answ

inessss [21]

Answer:

$\Delta S^{0}$ for the given reaction is -99.4 J/K

Explanation:

Balanced reaction: $\frac{1}{2}N_{2}(g)+\frac{3}{2}H_{2}(g)\rightarrow NH_{3}(g)$

$\Delta S^{0}=[1mol\times S^{0}(NH_{3})_{g}]-[\frac{1}{2}mol\times S^{0}(N_{2})_{g}]-[\frac{3}{2}mol\times S^{0}(H_{2})_{g}]$

where $S^{0}$ represents standard entropy.

Plug in all the standard entropy values from available literature in the above equation:

$\Delta S^{0}=[1mol\times 192.45\frac{J}{mol.K}]-[\frac{1}{2}mol\times 191.61\frac{J}{mol.K}]-[\frac{3}{2}mol\times 130.684\frac{J}{mol.K}]=-99.4J/K$

So, $\Delta S^{0}$ for the given reaction is -99.4 J/K

7 0

3 years ago