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3 years ago

A solution is made using 199.7 g of toluene and 80 g of benzene. What is the molality of the tolunene in the solution?

Chemistry

1 answer:

olga nikolaevna [1]3 years ago

6 0

Answer:

The molality of toluene is 7.748 molal

Explanation:

Step 1: Data given

Mass of toluene = 199.7 grams

Mass of benzene = 80.0 gram

Molar mass of benzene = 78.11 g/mol

Molar mass of toluene = 92.14 g/mol

Step 2: Calculate total mass

Total mass = mass of toluene + total benzene

Total mass = 199.7 grams + 80.0 grams

Total mass = 279.7 grams = 0.2797 kg

Step 3: Calculate moles of toluene

Moles toluene = mass toluene / molar mass toluene

Moles toluene = 199.7 grams / 92.14 g/mol

Moles toluene = 2.167 moles

Step 4: Calculate molality of toluene

Molality toluene = moles / mass solution

Molality = 2.167 moles / 0.2797 kg

Molality = 7.748 molal

The molality of toluene is 7.748 molal

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Answer:

Explanation:

Expression for capillary rise is as follows

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3 years ago

As you go down a family or group on the periodic table *

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Answer:

The elements become less reactive.

Explanation:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and reactivity increases because of greater electron affinity.

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased. The electron affinity decreases because of shielding effect and thus atom become less reactive.

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3 years ago

Calcium solid is placed in a solution of iron (III) chloride producing calcium chloride and iron solid

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Answer:

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Explanation:

Iron(III) chloride is also known as Iron trichloride and it has the molar mass value of 162.2 g/mol and density of 2.9 g/cm³.

The balanced equation for the chemical reaction between solid calcium and iron (III) chloride is given below as:

3Ca₍s₎ + 2FeCl₃ -------------------------------------------------------------> 3CaCl₂ + 2Fe₍s₎.

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3 years ago

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Answer:

Statements Y and Z.

Explanation:

The Van der Waals equation is the next one:

$nRT = (P + \frac{an^{2}}{V^{2}})(V -nb)$ (1)

The ideal gas law is the following:

$nRT = PV$ (2)

where n: is the moles of the gas, R: is the gas constant, T: is the temperature, P: is the measured pressure, V: is the volume of the container, and a and b: are measured constants for a specific gas.

As we can see from equation (1), the Van der Waals equation introduces two terms that correct the P and the V of the ideal gas equation (2), by the incorporation of the intermolecular interaction between the gases and the gases volume. The term an²/V² corrects the P of the ideal gas equation since the measured pressure is decreased by the attraction forces between the gases. The term nb corrects the V of the ideal gas equation, taking into account the volume occuppied by the gas in the total volume, which implies a reduction of the total space available for the gas molecules.

So, the correct statements are the Y and Z: the non-zero volumes of the gas particles effectively decrease the amount of "empty space" between them and the molecular attractions between gas particles decrease the pressure exerted by the gas.

Have a nice day!

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3 years ago

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erica [24]

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3 years ago

Read 2 more answers