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Andrew [12]
3 years ago
10

A student dissolves of styrene in of a solvent with a density of . The student notices that the volume of the solvent does not c

hange when the styrene dissolves in it. Calculate the molarity and molality of the student's solution. Be sure each of your answer entries has the correct number of significant digits.
Chemistry
1 answer:
raketka [301]3 years ago
8 0

Answer:

0.576M and 0.655m

Explanation:

<em>...Dissolves 15.0g of styrene (C₈H₈) in 250.mL of a solvent with a density of 0.88g/mL...</em>

<em />

Molarity is defined as moles of solute (Styrene in this case) per liter of solution whereas molality is the moles of solute per kg of solvent. Thus, we need to find the moles of styrene, the volume in liters of the solution and the mass in kg of the solvent as follows:

<em>Moles styrene:</em>

Molar mass C₈H₈:

8C = 12.01g/mol*8 = 96.08g/mol

8H = 1.005g/mol* 8 = 8.04g/mol

96.08g/mol + 8.04g/mol = 104.12g/mol

Moles of 15.0g of styrene are:

15.0g * (1mol / 104.12g) = 0.144 moles of styrene

<em>Liters solution:</em>

250mL * (1L / 1000mL) = 0.250L

<em>kg solvent:</em>

250mL * (0.88g/mL) * (1kg / 1000g) = 0.220kg

Molarity is:

0.144 moles / 0.250L =

<h3>0.576M</h3>

Molality is:

0.144 moles / 0.220kg =

<h3>0.655m</h3>
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How many grams of potassium chloride is produced with 2.5g of pure potassium
vazorg [7]

Answer:

The key to chemistry is to change everything to moles. Then when you have the answer in moles change the answer back to grams, liters, or whatever you want.

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calculate the gram molecular mass of potassium chlorate.

Chlorate is Cl with 3 oxygens. ate = saturated. Chlorine has seven valance electrons when it is saturated six of these electrons are used by oxygen ( 2 electrons per oxygen) leaving only 1 electron.

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25

122.4

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2.05 moles of Potassium Chlorate.

There is a 1:1 mole ratio. 1 mole of Potassium Chlorate will produce 1 mole of Potassium Chloride.

2.05 moles of Potassium Chlorate will produce 2.05 moles of Potassium Chloride.

Find the gram molecular mass of Potassium Chloride.

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2.05 moles x 74.4 grams/ mole = 15.2 grams

Explanation:

big brain ;)

3 0
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Strontium, a group 2 element with an electron configuration of 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 , will form a _____
amid [387]

Answer:

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Explanation:

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vlabodo [156]

Answer:

Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.

Hope this helps :)

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yuradex [85]

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