CHEMISTRY HIGH SCHOOL

Show the calculation of the molar mass (molecular weight) of a solute if a solution of 5.8 grams of the solute in 100 grams of water has a freezing point of 1.20oC. Kf for water is 1.86

Answers

Answer 1

Answer:

Answer : The molar mass of solute is, 89.9 g/mol

Explanation : Given,

Mass of solute = 5.8 g

Mass of solvent (water) = 100 g

Formula used :

$\Delta T_f=K_f* m\n\nT_f^o-T_f=T_f*\frac{\text{Mass of solute}* 1000}{\text{Molar mass of solute}* \text{Mass of water}}$

where,

$\Delta T_f$ = change in freezing point

$T_f^o$ = temperature of pure solvent (water) = $0^oC$

$T_f$ = temperature of solution = $1.20^oC$

$K_f$ = freezing point constant of water = $1.86^oC/m$

m = molality

Now put all the given values in this formula, we get

$(0^oC)-(1.20^oC)=1.86^oC/m* \frac{5.8g* 1000}{\text{Molar mass of solute}* 100g}$

$\text{Molar mass of solute}=89.9g/mol$

Therefore, the molar mass of solute is, 89.9 g/mol

Related Questions

A girl throws a rock into a pond. A leaf floating on the pond bobs up and down but does not change location on the pond's surface. Why not?
How many protons are in the radioactive isotope 40/19K
Fill in the missing reactant: NaOH + _____ → NaClO₂ + H₂O a. Cl₂ b. HCl c. HClO d. HClO₂ e. HClO₃
Using the atomic masses and relative abundance of the isotopes of nitrogen given below, determine the average atomic mass of nitrogen. N-14: 14.003 amu; 99.63% N-15: 15.000 amu; 0.37%
A student has a sample of isopropanol (C3H7OH) that has a mass of 78.6 g. The molar mass of isopropanol is 60.1 g/mol. How many moles of isopropanol are contained in this sample?

Which can associate a suspect and the firing of a gun?( its not b )
A) markings on the gun's exterior
B) markings on the casing
C) markings on the bullet
D) powder residues

Answers

One that is can associate a suspect and the firing of a gun is powder residues. The correct option is D.

What is gun power residue?

GSR is made up of unburned or partially burned gunpowder particles, soot, nitrates, and nitrites from powder combustion, primer particles (oxides of lead, antimony, and barium), and bullet or bullet jacket particles that are vaporized when a firearm is discharged.

Gunshotresidue (GSR) is a speck of vital trace evidence that assists forensic scientists in solving a wide range of firearm-related incidents.

The identification of the shooter, as well as bullet identification from a gunshot wound, aid in the reconstruction of a crime scene.

Powderresidues are one thing that can link a suspect to a gunshot.

Thus, the correct option is D.

For more details regarding gun powder, visit:

brainly.com/question/21765586

#SPJ5

Allicin contains 59.9 g of carbon, 21.7 g of hydrogen, 24.4 g of oxygen, and sulfur. What is the mass percent of sulfur in a 162 g sample of the compound?"

Answers

Answer: The mass percentage of sulfur in the given compound is 34.56 %.

Explanation:

We are given:

Mass of carbon in compound = 59.9 g

Mass of oxygen in compound = 24.4 g

Mass of Hydrogen in compound = 21.7 g

Mass of the compound = 162 g

Mass of sulfur in compound = $162-(59.9+24.4+21.7)=56g$

To calculate the mass percent of an element in a compound, we use the equation:

$\text{Mass percent of sulfur}=\frac{\text{Mass of sulfur in compound}}{\text{Mass of the compound}}* 100$

Putting values in above equation, we get:

$\text{Mass percent of sulfur}=(56g)/(162g)* 100 = 34.56\%$

Hence, the mass percentage of sulfur in the given compound is 34.56 %.

You can get the mass of sulfur on this compound by minus other element mass from total mass. So the mass is 162-59.9-21.7-24.4=56 g. The mass percent is 56/162*100%=34.57 %.

Which statement explains why a molecule of CH4 is nonpolar?(1) The bonds between the atoms in a CH4 molecule are polar.
(2) The bonds between the atoms in a CH4 molecule are ionic.
(3) The geometric shape of a CH4 molecule distributes the charges symmetrically.
(4) The geometric shape of a CH4 molecule distributes the charges asymmetrically.

Answers

The answer is the option (3) The geometric shape of a CH4 moleculedistributes the charges geometrically. the CH4 is a tetrahedral with theCarbon atom in the center and the four H atoms in the vertices of thetetrahedral. The C-H bond angles are all identical which makes themolecule perfectly symmetrical and so any dipolar moment will cancelmaking the molecule non polar.

The following statement explains why a molecule of $\text{CH}_4$ is nonpolar:

$\boxed{\left( 3 \right){\text{ The geometric shape of a C}}{{\text{H}}_4}{\text{ molecule distributes the charge symmetrically}}}$ .

Further explanation:

Covalent Bond

This type of bonding takes place when the bonded atoms mutually share electron pairs between them. It is also called the molecule bond. The chemical compounds formed as a result of this bond are called chemical compounds.

The polarity of any bond is primarily governed by two factors; electronegativity difference and symmetry. A bond is said to be polar if the bonded atoms have a considerable molecular bondelectronegativity difference between them. But if there is very small or no electronegativity difference between the bonded atoms, the resulting bond is nonpolar in nature.

Symmetry is another factor responsible for the polarity of the bond. The charge distribution is symmetrical in case symmetry is present in the molecule and as a result, the molecule is said to be nonpolar. But if there is asymmetry in the shape of the molecule, it will be polar in nature.

The electronegativity difference between carbon and hydrogen atoms in $\text{CH}_4$ molecule is very small or negligible so the bonds between the atoms in $\text{CH}_4$ are nonpolar in nature. But the hydrogen atoms are placed in symmetrical positions with respect to the central carbon atom, imparting symmetry to $\text{CH}_4$ molecule and therefore it is nonpolar (For structure, refer to the attached image).

Learn more:

Identification of ionic bonding: brainly.com/question/1603987
Chemical bonds in NaCl: brainly.com/question/5008811

Answer details:

Grade: High School

Chapter: Ionic and covalent compounds

Subject: Chemistry

Keywords: covalent bond, covalent compounds, CH4, carbon, hydrogen, symmetry, electronegativity difference, nonpolar.

The volume of a pond being studied for the effects of acid rain is 35 kiloliters (kL). There are 1,000 liters (L) in 1 kL and 1 mc032-1.jpg 106 microliters (mL) in 1 L. What is the volume of this pond in microliters?

Answers

The volume of a pond being studied for the effects of acid rain is 35 kiloliters (kL). There are 1,000 liters (L) in 1 kL and 1 x 10^6 microliters (mL) in 1 L.

35 kL (1,000 L/ 1kL) (1 x 10^6 microliters / 1 L) = 3.5 x 10^10 microliters

The volume of this pond in microliters is 3.5 x 10^10 microliters

Suppose a 1.30 g nugget of pure gold has zero net charge. What would be its net charge after it has 1.68% of its electrons removed?

Answers

Answer:

The net charge of 1.3 g nugget of pure gold after 1.68% of its electrons are removed is 559 C

Explanation:

When an atom gains electrons it becomes negatively charged. Conversely, when it looses electrons the atoms becomes positively charged thus

To solve this question, we rely on the relationship between the nmber of particles present in a given mass of an atom, Avogadro's number and number of moles, n

The given variables are

mass of pure gold nugget = 1.30 g

Quantity of electrons removed = 1.68% of electrons present in the gold sample

Molar mass of gold = 197 g/mol

Avogadro's number = 6.02 × 10²³ atoms/mole

qc = one electron charge = -1.06 × 10⁻¹⁹ C/electron

Electrical charge of gold nugget = 0 C

Number of electrons in one gold atom = 79 electrons

Solving for the number of prticles or gold atoms in 1.3 grams of gold we get

n mass/(molar mass) = 1.3/197 moles of gold = 0.0066 moles

number of particles in 0.0066 moles of gold N = n× $N_(A)$ = 0.0066 × 6.02 × 10²³ = 3.97 × 10²¹ atoms

since 79 electrons are present per particle we have

3.97 × 10²¹ × 79 = 3.14 × 10²³ electrons

quantity of elecrtrons removed = 1.68% of 3.14 × 10²³ electrons =1.68/100 × 3.14 × 10²³ electrons = 0.0168 × 3.14 × 10²³ electrons = 5.3 × 10²¹ electrons

The net charge of 5.3 × 10²¹ electrons = 5.3 × 10²¹ electrons × -1.06 × 10⁻¹⁹ C/electron =

5.59 × 10² C = 559 C

If 3.85 moles of aluminum (Al) metal, with a density of 2.70 g/mL, are needed for a chemical reaction, how many milliliters of aluminum are needed?Select one:
a. 1.43 mL Al
b. 18.9 mL Al
c. 38.5 mL Al
d. 281 mL Al

Answers

To find mL of Al needed, start by finding grams of Al that are being used in this reaction:
(3.85mol Al)(27.0g/mol Al)= 104g Al needed.

Since density is m/v, and we know the density and the mass, we can find the volume:
2.70g/mL = (104.g)/mL
Isolate mL:
(104.g)/(2.70g/mL) = 38.5mL needed which is answer C :)

Other Questions

How does evelyn hear music?

As air passes over a body of water, some of the carbon stored in the water is transferred to the atmosphere. This process is called _________________________________

David kept 100 grams of radioactive sodium in a container. He observed the amount of sodium left in the container after regular intervals of time and recorded them in the table shown below.Time (hours) Amount of sodium in container (in grams) 0 100 15 50 30 25 45 12.5 Based on the observations, which of these is most likely David's inference? A.The half life period of radioactive sodium is 15 hours. B.The half life period of radioactive sodium is 50 hours. C.The amount of sodium left in the container after 60 hours will be 10.5 grams. D.The amount of sodium left in the container after 60 hours will be 1.5 grams.

Select the ion.1)Cu2)PO4-33)SO2