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3 years ago

he number-average molecular weight of a polypropylene is 1,000,000 g/mol. Compute the degree of polymerization.

Chemistry

1 answer:

m_a_m_a [10]3 years ago

8 0

Answer:

The answer is "23765.4"

Explanation:

Motor weight average number $(\bar{M_n}) = 1000000 \frac{g}{mol}$

Poly condensation degree dependent on the average number of molecular weights is as follows:

$DP_n = \frac{\text{Mol.Wt Number Medium}}{\text{Monomer Unit Mol.Wt}}$

All monomer module, in this case, is propylene

Sunrise. Unit Wt = Mol. Propylene weight

$= \ Mol. \ Wt \ of \ C_3H_6\\\\= 3 \times 12.01 +6 \times 1.008 \ \ \frac{g}{mol}\\\\= 42.078 \frac{g}{mol}\\\\$

$DP_n = \frac{1000000}{42.078}\\\\$

$=23765.4$

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How does wind develop

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3 years ago

How many Moles of NAOH are present in 2.50L of 0.300 M NaOH?

maw [93]

<h3>Answer:</h3>

0.75 moles NaOH

<h3>Explanation:</h3>

We are given;

Volume of NaOH solution = 2.5 Liters

Molarity of NaOH = 0.300 M

We are required to calculate the moles of NaOH

We need to establish the relationship between moles, molarity and volume of a solution.

That would be;

Concentration/molarity = Moles ÷ Volume

Therefore;

Moles = Concentration × Volume

Thus;

Moles of NaOH = 0.300 moles × 2.50 L

= 0.75 moles

Therefore, the number of moles of NaOH is 0.75 moles

8 0

3 years ago

Calculate the pH of each of the following solutions: (a) 0.1000M Propanoic acid (HC3H5O2, Ka= 1.3x10-5 ) (b) 0.1000M sodium prop

jek_recluse [69]

(a) The pH of 0.1000 M propanoic acid (HC3H5O2) is 2.9.

(b) The pH of 0.1000 M sodium propanoate (NaC3H5O2) is 8.9.

<h3>Further explanation:</h3>

(a)

Given information:

The value of acid ionization constant for propanoic acid is 1.3 x $10^{-5}$ .

The initial concentration of propanoic acid is .

To calculate:

The pH of 0.1000 M propanoic acid solution.

Solution:

Propanoic acid is a weak acid. It ionizes partially in water as follows:

The expression for acid dissociation constant is,

…… (1)

Here,

is ionization constant of propanoic acid.

is the equilibrium concentration of propanoate ion.

is the equilibrium concentration of hydronium ion.

is the equilibrium concentration of propanoic acid.

ICE table (1):

Refer ICE table (1),

Substitute the values form the ICE table (1) in equation (1).

The approximation x is very small is valid. Therefore, the value of x can be neglected. Above equation can be modified as,

Rearrange above equation for x.

…… (2)

Substitute for in equation (2) to calculate the value of x.

Therefore, from the ICE table (1) the concentration of hydronium ion is,

The negative logarithm of hydronium ion concentration is defined as the pH of the solution. Mathematically,

…… (3)

Substitute for in equation (3) to calculate the pH of the solution.

(b)

Given information:

The value of acid ionization constant for propanoic acid is .

The initial concentration of sodium propanoate is .

To calculate:

The pH of 0.1000 M sodium propanoate solution.

Solution:

Sodium propanoate is conjugate base of weak propanoic acid. It undergoes hydrolysis in water to yield hydroxide ion in the solution as follows:

…… (4)

Propanoic acid is a weak acid. It ionizes partially in water as follows:

…… (5)

Dissociation reaction for water is written as follows:

…… (6)

From equation (4), (5), and (6) the relationship between and is,

…… (7)

Substitute for and for in equation (7).

ICE table (2):

The expression for base dissociation constant is,

…… (8)

Here,

is base ionization constant.

is the equilibrium concentration of propanoate ion.

is the equilibrium concentration of hydroxide ion.

is the equilibrium concentration of propanoic acid.

From the ICE table (2),

Substitute the values form the ICE table (2) in equation (8).

The approximation y is very small is valid. Therefore, the value of y can be neglected. Above equation can be modified as,

Rearrange above equation for y.

…… (9)

Substitute for in equation (9) to calculate the value of y.

Therefore, from the ICE table (2) the concentration of hydroxide ion is,

The negative logarithm of hydroxide ion concentration is defined as pOH of the solution. Mathematically,

…… (10)

Substitute for in equation (10) to calculate pOH of the solution.

The relation between pH and pOH is as follows:

…… (11)

Substitute 5.057 for pOH in equation (11) to calculate the pH of the solution.

(c)

Given information:

The value of acid ionization constant for propanoic acid is .

The initial concentration of sodium propanoate is .

To calculate:

The pH of 0.1000 M sodium propanoate and 0.1000 M propanoic acid solution.

Solution:

Propanoic acid is a weak acid, and sodium propanoate is salt of the conjugate base of propanoic acid. Thus, propanoic acid and sodium propanoate will form a buffer system.

The pH of the buffer solution can be determined with the help of the Henderson-Hasselbalch equation. Mathematically,

For propanoic acid and sodium propanoate buffer system, the Henderson-Hasselbalch equation can be modified as,

…… (12)

The negative logarithm of acid ionization constant is equal to .

…… (13)

Substitute for in equation (13).

Substitute for , for and 4.9 for in equation (12).

Learn more:

1. About Henderson-Hasselbalch equation brainly.com/question/12999557

2. Learn more about how to calculate moles of the base in given volume brainly.com/question/4283309

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Ionic equilibria

Keywords: ionic equilibrium, propanoic acid, sodium propanoate, ionization constant, weak acid, conjugate base, equilibrium concentration, hydronium ion, hydroxide ion, pH, pOH, ICE table, negative logarithm, buffer solution, Henderson-Hasselbalch equation, 0.1000 M, 4.9, 8.9, 2.9.

3 0

3 years ago

Read 2 more answers

The fuel used to power the booster rockets on space shuttles is a mixture of aluminum metal and ammonium perchlorate. The follow

pishuonlain [190]

Answer:

Therefore 373 mole of Al produce 746 mole of water.

Explanation:

Given reaction is

3 Al+3NH₄ClO₄→Al₂O₃+AlCl₃+3NO+6H₂O

From the above reaction it is clear that 3 mole of Al produce 6 mole of water.

Therefore

3 mole of Al produce 6 mole of water.

1 mole of Al produce $\frac{6}{3}$ mole of water.

373 mole of Al produce $\frac{6\times 373}{3}$ mole of water.

= 746 mole of water.

Therefore 373 mole of Al produce 746 mole of water.

7 0

3 years ago

What is going to happen to a balloon filled with helium that is left in a car over night when the temperature drops approximatel

Scilla [17]

Answer:

<u><em>When balloon filled with the helium gas is left in the car at night along with the decrease in temperature the size of the balloon will get smaller or it will look like little deflated</em></u>.The above observation can be explained on the basis of Charles law:The law states that 'under constant pressure ,the volume occupied by the gas is directly proportional to the temperature of the gas'. (At constant pressure)Temperature desecrate volume will also decreases and vice versa.So, with decrease in temperature at night the temperature of the gas in the balloon will also get decreased due to which the volume of the balloon will also get decreased.

Explanation:

6 0

3 years ago