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3 years ago

Which liquid has the highest vapor pressure at 75°C?

Chemistry

1 answer:

Temka [501]3 years ago

4 0

Answer:

1) Ethanol

Explanation:

If we will have interactions we will need more energy to break them in order to go from liquid to gas. If we need more energy, therefore, the temperature will be higher.

In this case, we can discard the propanone because this molecule don't have the ability to form hydrogen bonds. (Let's remember that to have hydrogen bonds we need to have a hydrogen bond to a heteroatom, O, N, P or S).

Then we have to analyze the hydrogen bonds formed in the other molecules. For ethanol, we will have only 1 hydrogen bond. For water and ethanoic acid, we will have 2 hydrogen bonds, therefore, we can discard the ethanol.

For ethanoic acid, we have 2 intramolecular hydrogen bonds. For water we have 2 intermolecular hydrogen bonds, therefore, the strongest interaction will be in the ethanoic acid.

The closer boiling point to the 75ºC is the ethanol (boiling point of 78.8 ºC) therefore these molecules would have enough energy to break the hydrogen bonds and to past from liquid to gas.

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During fusion _____. hydrogen atoms are split apart U-235 atoms are created helium atoms are created uranium atoms are fused tog

musickatia [10]

The correct answer is the second option. During fusion, uranium atoms are fused together. Fusion reaction happens when two or more nuclei combine or collide to form an element with a higher atomic number. In this process, some of the matter of the fusing nuclei is converted to energy.

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4 years ago

One reaction involved in the conversion of iron ore to the metal is FeO(s) + CO(g) → Fe(s) + CO2(g) Use Hess’s Law to calculate

Ugo [173]

Answer:

$\delta H_{rxn} = -66.0 \ kJ/mole$

Explanation:

Given that:

$3FeO_3_{(s)}+CO_{(g)} \to 2Fe_3O_4_{(s)} +CO_{2(g)} \ \ \delta H = -47.0 \ kJ/mole -- equation (1) \\ \\ \\ Fe_2O_3_{(s)} +3CO_{(g)} \to 2FE_{(s)} + 3CO_{2(g)} \ \ \delta H = -25.0 \ kJ/mole -- equation (2) \\ \\ \\ Fe_3O_4_{(s)} + CO_{(g)} \to 3FeO_{(s)} + CO_{2(g)} \ \delta H = 19.0 \ kJ/mole -- equation (3)$

From equation (3) , multiplying (-1) with equation (3) and interchanging reactant with the product side; we have:

$3FeO_{(s)} + CO_{2(g)} \to Fe_3O_4_{(s)} + CO_{(g)} \ \delta H = -19.0 \ kJ/mole -- equation (4)$

Multiplying (2) with equation (4) ; we have:

$6FeO_{(s)} + 2CO_{2(g)} \to 2Fe_3O_4_{(s)} + 2CO_{(g)} \ \delta H = -38.0 \ kJ/mole -- equation (5)$

From equation (1) ; multiplying (-1) with equation (1); we have:

$2Fe_3O_4_{(s)} +CO_{2(g)} \to 3FeO_3_{(s)}+CO_{(g)} \ \ \delta H = 47.0 \ kJ/mole -- equation (6)$

From equation (2); multiplying (3) with equation (2); we have:

$3 Fe_2O_3_{(s)} +9CO_{(g)} \to 6FE_{(s)} + 9CO_{2(g)} \ \ \delta H = -75.0 \ kJ/mole -- equation (7)$

Now; Adding up equation (5), (6) & (7) ; we get:

$6FeO_{(s)} + 2CO_{2(g)} \to 2Fe_3O_4_{(s)} + 2CO_{(g)} \ \delta H = -38.0 \ kJ/mole -- equation (5)$

$2Fe_3O_4_{(s)} +CO_{2(g)} \to 3FeO_3_{(s)}+CO_{(g)} \ \ \delta H = 47.0 \ kJ/mole -- equation (6)$

$3 Fe_2O_3_{(s)} +9CO_{(g)} \to 6FE_{(s)} + 9CO_{2(g)} \ \ \delta H = -75.0 \ kJ/mole -- equation (7)$

$FeO \ \ \ + \ \ \ CO \ \ \to \ \ \ \ Fe_{(s)} + \ \ CO_{2(g)} \ \ \ \delta H = - 66.0 \ kJ/mole$

$\delta H_{rxn} = \delta H_1 + \delta H_2 + \delta H_3$ (According to Hess Law)

$\delta H_{rxn} = (-38.0 + 47.0 + (-75.0)) \ kJ/mole$

$\delta H_{rxn} = -66.0 \ kJ/mole$

8 0

3 years ago

What elements are being reduced and oxidized in this chemical formula?

dangina [55]

Answer: The element Na (Sodium) is getting oxidized and Hydrogen is getting reduced.

Explanation:

Oxidation reactions are the reactions in which addition of oxygen takes place.

Reduction reactions are the reactions in which loss of oxygen takes place.

For a given reaction:

$2Na(s)+2H_2O(l)\rightarrow H_2(g)+2NaOH(aq.)$

Sodium is getting oxidized because there is an addition of reaction with that element.

Hydrogen is getting reduced because there is a removal of oxygen with that element.

3 0

3 years ago

Which symbol can be used to indicate the pressure at which a chemical reaction is carried out? 25 degrees Celsius over a right a

jolli1 [7]

Answer:

2 atm

Explanation:

Chemical reactions are carried out at a certain rate. Sometimes that rate is quite slow, so we want to speed things up, which is usually used by increasing temperature, increasing pressure or adding a catalyst (a substance that increases the rate without changing itself).

If this is the case, then, when writing a chemical equation, we state these special conditions over a right arrow.

Now let's look at the answers:

- 25°C is a value and unit of temperature

- ∆ is a symbol that denotes change

- 2 atm is a value and unit of pressure (atmosphere is old unit for pressure)

- Pt is a chemical symbol for platinum, an element often used as a catalyst.

So, the correct answer is C) 2 atm

7 0

3 years ago

Read 2 more answers

A 0.590 gram sample of a metal, M, reacts completely with sulfuric acid according to:M(s) +H2SO4(aq) --> MSO4(aq) +H2(g)A vol

photoshop1234 [79]

Answer:

MM = 58.41 g

Explanation:

First, the data we have is according to the hydrogen which is exerting pressure. To solve this, we need to use the ideal gas equation:

PV = nRT (1)

the molar mass of any compound is calculated like this:

MM = m/n (2)

So, from (1) we solve for the moles (n) and then, this value is replace in (2).

However, before we do all that, we need to gather all the correct data.

All the species in the reaction are solid or aqueous state, with the exception of hydrogen, which is gaseous. Hydrogen is collected over water, therefore, is exerting some pressure too. The problem is not indicating if the acid or any other species is exerting pressure, so we will assume that only hydrogen and water are exerting pressure.

The total pressure exerted by the system would be:

P = Pw + PH2 (3)

We already know the total pressure which is 756 torr.

This experiment is taking place at 25 °C (298.15 K), and at this temperature, we have a reported value for water pressure which is 23.8 Torr.

Let's solve for PH2:

PH2 = P - Pw

PH2 = 756 - 23 = 733 Torr

Now, with this value, and the volume and temperature, we can calculate the moles of H2:

n = PV/RT

But first, let's convert the pressure to atm:

PH2 = 733 Torr / 760 torr * 1 atm = 0.9644 atm

now, solving for n:

n = 0.9644 * (0.255) / 0.082 * 298.15

n = 0.0101 moles

Now that we have the moles, we know that the metal and the hydrogen has a mole ratio of 1:1 according to the reaction, so, this means that:

moles M = moles H2 = 0.0101 moles

We have the moles of the metal and the mass, we can calculate the molar mass using expression (2):

MM = 0.590/0.0101

MM = 58.41 g/mol

This is the molar mass of the metal

8 0

3 years ago