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3 years ago

How do catalysts affect energy of reactions

Chemistry

2 answers:

Strike441 [17]3 years ago

5 0

Explanation:

A catalyst lowers the activation energy of a reaction allowing them to proceed faster than they would naturally. Activation energy is the free energy that is required to be input in the reactant side to activate them to the transition state after which the reaction proceeds spontaneously to products.

An example of a catalyst is platinum, that is put in the exhaust of cars, to help convert carbon monoxide to carbon dioxide before it is emitted into the air.

natima [27]3 years ago

3 0

Answer: they lower these activation required for the reactions to take place.

Explanation:

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A 13.30 gram sample of an organic compound containing C, H and O is analyzed by combustion analysis and 13.00 grams of CO2 and 2

a_sh-v [17]

Answer: The empirical and molecular formula for the given organic compound is $CHO_2$ and $C_2H_2O_4$

Explanation:

The chemical equation for the combustion of hydrocarbon having carbon, hydrogen and oxygen follows:

$C_xH_yO_z+O_2\rightarrow CO_2+H_2O$

where, 'x', 'y' and 'z' are the subscripts of Carbon, hydrogen and oxygen respectively.

We are given:

Mass of $CO_2=13.00g$

Mass of $H_2O=2.662g$

We know that:

Molar mass of carbon dioxide = 44 g/mol

Molar mass of water = 18 g/mol

For calculating the mass of carbon:

In 44 g of carbon dioxide, 12 g of carbon is contained.

So, in 13.00 g of carbon dioxide, $\frac{12}{44}\times 13.00=3.54g$ of carbon will be contained.

For calculating the mass of hydrogen:

In 18 g of water, 2 g of hydrogen is contained.

So, in 2.662 g of water, $\frac{2}{18}\times 2.662=0.296g$ of hydrogen will be contained.

Mass of oxygen in the compound = (13.30) - (3.54 + 0.296) = 9.464 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{3.54g}{12g/mole}=0.295moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{0.296g}{1g/mole}=0.296moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{9.465g}{16g/mole}=0.603moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.295 moles.

For Carbon = $\frac{0.295}{0.295}=1$

For Hydrogen = $\frac{0.296}{0.295}=1$

For Oxygen = $\frac{0.603}{0.295}=2.044\approx 2$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H : O = 1 : 1 : 2

Hence, the empirical formula for the given compound is $CHO_2$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 90.04 g/mol

Mass of empirical formula = 45 g/mol

Putting values in above equation, we get:

$n=\frac{90.04g/mol}{45g/mol}=2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(1\times 2)}H_{(1\times 2)}O_{(2\times 2)}=C_2H_2O_4$

Hence, the empirical and molecular formula for the given organic compound is $CHO_2$ and $C_2H_2O_4$

3 0

3 years ago

Which of the following describes a covalent bond?

BaLLatris [955]

I think it is C, because a covalent bond is a distribution of 2 atoms to 1 electron, meaning they are sharing and not exchanging, and the electronegravity would be above 1.7

5 0

3 years ago

Read 2 more answers

Identify the most acidic hydrogens in each of the following molecules. Give the structure of the enolate ion arising from deprot

san4es73 [151]

Answer:

See explanation below (Brainlist please)

Explanation:

First of all, we need to understand what is an acidic hydrogen.

An acidic hydrogen, is the atom of hydrogen which is more propense to undergo an acid base reaction, and form a stable ion or molecule in the process.

In other words, is the hydrogen that is more vulnerable to get substracted in an acid base reaction to form another compound.

Knowing this information, gives us an idea of how a molecule can be formed and which kind of compound is formed.

Now, in this question, we have 5 molecules. Each of them is either a ketone or aldehyde, so this mean that we have the carbonile group (C = O), which means that is easier to identify the acidic hydrogen. This is because the Carbonile group is an attractor group, so, it will attract the charges by inductive effect (in some cases by resonance), and the molecule is more stable.

This can be shown by drawing the enolate ion that is formed once the molecule undergo the acid base reaction. As it's an enolate form that we are looking for, then it means that the ketone or aldehyde is undergoing an electrofilic attack with a base. This base will substract the most acidic hydrogen to form a better and stable enolate. The acidic hydrogen and the enolate form can be seen in the attached picture.

a) In the case of acetaldehyde, the most acidic will be the hydrogen of carbon 2, because the hydrogen from the carbonile, once it's substracted, the charge of the carbon cannot be stabilized by resonance. Carbon 2 hydrogens, can do this job easily.

b) Propanal happens something similar to acetaldehyde, the terminal hydrogen cannot be substracted, and carbon 3, once the hydrogen is gone, the negative charge cannot be stabilized by resonance, so hydrogens of carbon 2 can do this.

c) in the case of acetone, is easier to look because we only have the C = O between two methyl group, so you can use either carbon 1 or 3 to do the job.

d) 4 heptanone the most acidic hydrogen would be carbon 3 or 5, because they are closer to the C=O and the ion can be stabilized by resonance.

e) Finally in ciclopentanone, the most acidic hydrogen would be carbon 2 or 5.

See picture for a better understanding.

Hope it helps.