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3 years ago

Please help 10 points!!!

Chemistry

1 answer:

dalvyx [7]3 years ago

6 0

<span>the average atomic mass of this element is 39.95 u</span>

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Are you for or against transgender? why?

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Explanation:

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3 years ago

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In a certain industrial process involving a heterogeneous catalyst, the volume of the catalyst (in the shape of a sphere) is 10.

olga nikolaevna [1]

Answer:

a. The second run will be faster.

d. The second run has twice the surface area.

Explanation:

The rate of a reaction is proportional to the surface area of a catalyst. Given the volume (V) of a sphere, we can find its surface area (A) using the following expression.

$A=\pi ^{1/3} (6V)^{2/3}$

The area of the 10.0 cm³-sphere is:

$A=\pi ^{1/3} (6.10.0)^{2/3}=22.4cm^{2}$

The area of each 1.25 cm³-sphere is:

$A=\pi ^{1/3} (6. 1.25)^{2/3}=5.61cm^{2}$

The total area of the 8 1.25cm³-spheres is 8 × 5.61 cm² = 44.9 cm²

The ratio of 8 1.25cm³-sphere to 10.0 cm³-sphere is 44.9 cm²/22.4 cm² = 2.00

Since the surface area is doubled, the second run will be faster.

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3 years ago

(plz anwser all questions 15 points)

Diano4ka-milaya [45]

Answer:

1. B, D,

2.A, F

Explanation:

1. According to the law of conservation of mass, In a course of chemical reaction, matter can neither be created nor destroyed but can be changed from one form to another. This means the amount of matter at the begining and ending of a reaction must be thesame.

2. Chemical reaction is not easily reversible. when gas is produced, provided the reaction system is an open system, the gas cannot be recovered and the reactants cannot be recovered from the products. likewise color change are attributed to chemical reaction

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3 years ago

What do nuclear reactions change in the atom?

Ganezh [65]

Nuclear reactions happen inside the nucleus,so it changes the protons and neutrons

5 0

3 years ago

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of an unknown protein are dissolved in enough solvent to make 5.00mL of solution. The osmotic pressure of this solution is measu

krok68 [10]

The question is incomplete . The complete question is :

100 mg of an unknown protein are dissolved in enough solvent to make 5.00mL of solution. The osmotic pressure of this solution is measured to be 0.107atm at 25.0°C. Calculate the molar mass of the protein. Round your answer to 3 significant digits.

Answer: The molar mass of the protein is $4.57\times 10^3g/mol$

Explanation:

$\pi =CRT$

$\pi=i\times \frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}\times RT$

where,

$\pi$ = osmotic pressure of the solution = 0.107 atm

i = Van't hoff factor = 1 (for non-electrolytes)

Mass of solute (protein) = 100 mg = 0.1 g (Conversion factor: 1 g = 1000 mg)

Volume of solution = 5.00 mL

R = Gas constant = $0.0821\text{ L.atm }mol^{-1}K^{-1}$

T = temperature of the solution = $25^oC=[273+25]=298K$

Putting values in above equation, we get:

$0.107=1\times \frac{0.1\times 1000}{\text{Molar mass of insulin}\times 5.00}\times 0.0821\text{ Latm }mol^{-1}K^{-1}\times 298K\\\\\text{molar mass of protein}$

$\text{molar mass of protein}=4.57\times 10^3g/mol$

Hence, the molar mass of the protein is $4.57\times 10^3g/mol$

7 0

3 years ago