Chemistry, 24.02.2020 23:53 ErrorNameTaken505

3.56 grams of an unknown non-electrolytic solute were dissolved in 40.0 g of water (Kfp = 1.86 K/m). If the freezing point of the solution was -0.820 oC, determine the molar mass of the unknown solute.

Answers: 1

Show answers

Answers

Answer from: powellmj9216

201.8 g/mol is the molar mass for the compound

Explanation:

To solve this, we apply the formula for freezing point depression:

Freezing point for solution = - (Kf . m - Freezing point por pure solvent)

Freezing point for solution = - Kf . m + Freezing point por pure solvent

Freezing point for pure solvent = 0°C, therefore - 0.820°C = - Kf . m

Kf = 1.86 °C/m ; m = molality (mol/kg), moles of solute in 1kg of solvent

It is more common to say 1.86 °C/m instead of K/m

0.820°C / 1.86 m°C = m → m = 0.441 molal (These moles are in 1kg of solvent, but our mass is 40 g, 1kg = 1000g)

We determine the moles of solute → Molal . mass of solvent

0.441 mol/1000g . 40 g = 0.0176 moles

Molar mass → mass of compound (g) in 1 mol → 3.56 g / 0.0176 moles = 201.8 g/mol

Answer from: Quest

Answerthe half-reaction having the greatest tendency to occur at the anode: i₂(aq) + 2e⁻ ⇄ 2i⁻ ; e = +0.53 v====== $\begin{aligned} \text{i}_2\text{\footnotesize (aq)}+2\,\text{e}^{-} & \rightleftharpoons 2\,\text{i}^{-}\text{\footnotesize (aq)}& \text{e} & = +0.53\text{ v} \\ \text{co}^{3+}\text{\footnotesize (aq)} + \text{e}^{-} & \rightleftharpoons \text{co}^{2+}\text{\footnotesize (aq)} & \text{e} & = +1.80\text{ v} \\ \text{o}_2\text{\footnotesize (g)}+4\,\text{h}^{+}\text{\footnotesize (aq)} + 4\,\text{e}^{-} & \rightleftharpoons 2\,\text{h}_2\text{o}\text{\footnotesize(l)}& \text{e} & = +1.23\text{ v} \\ \end{aligned}$ oxidation occurs at the anode. we must therefore find the half-reaction with the greatest tendency to oxidize.the given values of e are reduction potentials (the form of the half-reactions are of reduction).the lower the reduction potential, the higher the potential to oxidize. the half-cell with the lowest reduction potential will have the greatest tendency to oxidize at the anode.the half-reaction having the greatest tendency must be i₂(aq) + 2e⁻ ⇄ 2i⁻ e = +0.53 vbecause its reduction potential is the lowest out of the three.

Answer from: Quest

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.

Other questions on the subject: Chemistry

Chemistry, 21.06.2019 17:40, monkey2865

If 10.0 ml of the solution on the right are withdrawn from the 100 ml beaker and diluted again in a similar manner, what is the new concentration? m nacl

Answers: 2

continue

Chemistry, 21.06.2019 22:30, 12375819

For the following, determine the type of reaction and then give products.

Answers: 2

continue

Chemistry, 22.06.2019 00:30, mannster03

This active feature of earth's crust in building mountain ranges as well as islands. this feature is a a) cavern. b) earthquake. c) mountain. d) volcano.

Answers: 2

continue

Chemistry, 22.06.2019 03:30, acaciacoats

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Answers: 2

continue

You know the right answer?

3.56 grams of an unknown non-electrolytic solute were dissolved in 40.0 g of water (Kfp = 1.86 K/m)....