A testable explanation that's supported or refuted is called an

Why is computational chemistry important?

Tema [17]

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4 0

3 years ago

A certain reaction with an activation energy of 185 kJ/mol was run at 505 K and again at 525 K . What is the ratio of f at the h

frosja888 [35]

Answer:

The ratio of f at the higher temperature to f at the lower temperature is 5.356

Explanation:

Given;

activation energy, Ea = 185 kJ/mol = 185,000 J/mol

final temperature, T₂ = 525 K

initial temperature, T₁ = 505 k

Apply Arrhenius equation;

$Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ]$

Where;

$\frac{f_2}{f_1}$ is the ratio of f at the higher temperature to f at the lower temperature

R is gas constant = 8.314 J/mole.K

$Log(\frac{f_2}{f_1} ) = \frac{E_a}{2.303 \times R} [\frac{1}{T_1} -\frac{1}{T_2} ]\\\\Log(\frac{f_2}{f_1} ) = \frac{185,000}{2.303 \times 8.314} [\frac{1}{505} -\frac{1}{525} ]\\\\Log(\frac{f_2}{f_1} ) = 0.7289\\\\\frac{f_2}{f_1} = 10^{0.7289}\\\\\frac{f_2}{f_1} = 5.356$

Therefore, the ratio of f at the higher temperature to f at the lower temperature is 5.356

5 0

3 years ago

What is the name of this compound of P4O10

romanna [79]

Phosphorus pentoxide is a chemical compound with molecular formula P4O10 This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydrating agent.

7 0

4 years ago

What mass of calcium carbonate is produced from 5.11 mol of sodium carbonate?

a_sh-v [17]

Answer:

There is 541.6 grams of calcium carbonate produced from 5.11 moles

Explanation:

Step 1: Data given

Number of moles of sodium carbonate ( Na2CO3) = 5.11 moles

Molar mass of sodium Carbonate:

⇒ Molar mass of Sodium = 22.99 g/mole

⇒ Molar mass of Carbon = 12.01 g/mole

⇒ Molar mass of Oxygen = 16 g/mole

Molar mass of Na2CO3 = 2* 22.99 + 12.01 + 3*16 = 105.99 g/mole

Step 2: Calculate mass of 5.11 moles of sodium carbonate

mass = number of moles of sodium carbonate * Molar mass of sodium carbonate

mass = 5.11 moles * 105.99 g/moles = 541.6 grams ≈ 542 grams

There is 541.6 grams of calcium carbonate produced from 5.11 moles Na2CO3

3 0

3 years ago

Which of the following does not influence the effectiveness of a detergent? A-air temperature B-water temperature C-energy appli

Natasha2012 [34]

A-air temperature does not influence the effectiveness of a detergent

$\boxed{\boxed{\bold{Further~explanation}}}$

In chemical reactions several factors influence among others:

1. Temperature

The temperature of the reaction that is raised will cause the particles to move more actively so that collisions between particles will become more frequent so that the speed of chemical reactions will be greater

2. Pressure

Addition of pressure will increase the concentration because the volume is reduced, a greater concentration will accelerate the reaction

3. Concentration / substance level

The greater the level, the more substances dissolved and involved in the reaction, thereby increasing the speed of the reaction

4. Stirring

The mechanical force applied to the solution that reacts will cause more collisions to accelerate the reaction

5 Catalysts

Addition of a catalyst to accelerate the reaction without reaction with reactant substances

Detergents are used as cleaning removers of dirt on clothes or oily/fatty items

The main structure of detergent is surfactant which has hydrophobic (binding fat) and hydrophilic (which binds water) parts

Surfactants also function to reduce water surface tension so that it is easier to bind dirt

Surfactants can be anionic in which there are derivatives of Benzene, namely: Alkyl Benzene Sulfonate obtained from sulfonation reactions where hydrogen in benzene is substituted by sulfonate groups (HSO₃⁻) reaction with sulfuric acid (H₂SO₄)

If we see the answer choices:

A. Air temperature

Air does not play a role in the reaction or cleaning process of dirt by detergents, so it is not an effective or ineffective factor in detergent cleaning

B. Water temperature

The right water temperature by adjusting the conditions of clothing materials will increase the effectiveness of detergents, for example, hot temperatures suitable for lifting oil/oil stains, warm/cold temperatures for clothes that are not too dirty and made of silk/wool

C. Energy gave

The energy in the cleaning process can be done through mechanical energy so that the collision between the particles of detergent and dirt will occur more so that faster removal of dirt

D. the length and frequency of the treatment

Sufficient time and the frequency of contact between detergents and ingredients, especially for dirty and hard-to-lose materials, will make removal of dirt better

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