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4 years ago

Una muestra de 258.4 g de etanol (C2H5OH) se quemó en una bomba calorimétrica

Chemistry

1 answer:

Ilia_Sergeevich [38]4 years ago

4 0

Answer:

Explanation:

Unclear question.

I infer you want a clear rendering, which reads;

A 258.4 g sample of ethanol (C2H5OH) was burned in a calorimetric pump using a Dewar glass. As a consequence, the water temperature rose to 4.20 ° C.

If the heat capacity of the water and the surrounding glass was 10.4 kJ / ° C, calculate the heat of combustion of one mole of ethanol.

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Given 4.80g of ammonium carbonate, find:

V125BC [204]

Answer:

1) 0.05 mol.

2) 0.1 mol.

3) 0.05 mol.

4) 0.4 mol.

5) 2.4 x 10²³ molecules.

Explanation:

1) Number of moles of the compound:

no. of moles of ammonium carbonate = mass/molar mass = (4.80 g)/(96.09 g/mol) = 0.05 mol.

2) Number of moles of ammonium ions :

Ammonium carbonate is dissociated according to the balanced equation:

(NH₄)₂CO₃ → 2NH₄⁺ + CO₃²⁻.

It is clear that every 1.0 mole of (NH₄)₂CO₃ is dissociated to produce 2.0 moles of NH₄⁺ ions and 1.0 mole of CO₃²⁻ ions.

∴ The no. of moles of NH₄⁺ ions in 0.05 mol of (NH₄)₂CO₃ = (2.0)(0.05 mol) = 0.1 mol.

3) Number of moles of carbonate ions :

Ammonium carbonate is dissociated according to the balanced equation:

(NH₄)₂CO₃ → 2NH₄⁺ + CO₃²⁻.

It is clear that every 1.0 mole of (NH₄)₂CO₃ is dissociated to produce 2.0 moles of NH₄⁺ ions and 1.0 mole of CO₃²⁻ ions.

∴ The no. of moles of CO₃²⁻ ions in 0.05 mol of (NH₄)₂CO₃ = (1.0)(0.05 mol) = 0.05 mol.

4) Number of moles of hydrogen atoms:

Every 1.0 mol of (NH₄)₂CO₃ contains:

2.0 moles of N atoms, 8.0 moles of H atoms, 1.0 mole of C atoms, and 3.0 moles of O atoms.

∴ The no. of moles of H atoms in 0.05 mol of (NH₄)₂CO₃ = (8.0)(0.05 mol) = 0.4 mol.

5) Number of hydrogen atoms:

It is known that every mole of a molecule or element contains Avogadro's number (6.022 x 10²³) of molecules or atoms.

Using cross multiplication:

1.0 mole of H atoms contains → 6.022 x 10²³ atoms.

0.4 mole of H atoms contains → ??? atoms.

∴ The no. of atoms in 0.4 mol of H atoms = (6.022 x 10²³ molecules)(0.4 mole)/(1.0 mole) = 2.4 x 10²³ molecules.

8 0

3 years ago

Need help ASAP... The diagram shows a box in the periodic table.. what is the atomic number of the element??

ad-work [718]

The atomic number is 15

4 0

3 years ago

A person riding a bike has a mass of 55kg. They are moving with a velocity of 2m/s. What is the Kinetic Energy of the person?

ZanzabumX [31]

KE=0.5 • mv2
KE is 110 Joules

8 0

3 years ago

Construction crews sometimes use this reaction for welding underwater structures:

meriva

Answer:

5 moles of iron formed

Explanation:

Given data:

Moles of iron formed = ?

Moles of iron oxide react = 2.50 mol

Solution:

Chemical equation:

Fe₂O₃ + 2Al → Al₂O₃ + 2Fe

Now we will compare the moles of iron with iron oxide.

Fe₂O₃ : Fe

1 ; 2

2.50 : 2×2.50 = 5 mol

5 0

3 years ago

Your company has developed an organic molecule with commercial potential and you know how to produce it in the lab. You want to

Lena [83]

Answer:

(B) continually remove products

(C) increase the concentration of reactants

Explanation:

You can drive the production rate of an equilibrium reaction by handling several factors: temperature, reactant concentrations, and product concentrations are the main of those factors.

The thermodynamic variable that tells whether a chemical reaction is spontaneous is the free energy, ΔG:

ΔG < 0 represents a driving force in the forward direction,

ΔG > 0 represents a driving force in the reverse direction,

ΔG = 0 represents that the system is at equilibrium.

ΔG is related with ΔG° per the expression:

ΔG = ΔG° + RT ln Q

Where Q represents the ratio between the molar concentration of the products (each raised to its stoichiometric coefficient) and the molar concentrations of the reactants (each raised to its stoichiometric coefficient).

Since, you want to increase your production, means you want to favor the forward reaction and that means that you want to make ΔG more negative.

So, you want to make the term RT lnQ more netative.

Logarithm function of a rational expression gets more negative when the numerator decreases or the denominator increases.

So, you want either reduce the amount of products or increase the amount of reactants, which is given by the options B and C:

(B) continually remove products

(C) increase the concentration of reactants

Enzymes are a kind of catalyst. In an equilibrium reaction, a catalys speeds up both the forward and reverse reaction rates equally, so the equilibrium concentrations will not change. So, adding an enzyme (choice A) would help if you, continually remove products (B) or increase the concentration of reactants (C).

Adding products to get the reaction primed (D) will not help because that just would drive to the consumption of part of the products to obtain some reactants until reaching the equilibrium.

8 0

3 years ago