1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
grigory [225]
3 years ago
10

What is the freezing point of a solution made with 1.31 mol of CHCl3 in 530.0 g of CCl4 (Kf =29.8 degrees C/m, Freezing point of

pure solvent = -22.9 degrees C)?
Chemistry
1 answer:
Allisa [31]3 years ago
6 0

73.606 °C is the freezing point of the solution made with with 1.31 mol of CHCl3 in 530.0 g of CCl4.

Explanation:

Data given:

number of moles of CHCl3 = 1.31 moles

mass of solvent CHCl3 = 530 grams or 0.53 kg

Kf = 29.8 degrees C/m

freezing point of pure solvent or CCl4 =  -22.9 degrees

freezing point = ?

The formula used to calculate the freezing point of the mixture is

ΔT = iKf.m

m=  molality

molality = \frac{moles of solute}{mass of solvent in kilograms}

putting the value in the equation:

molality= \frac{1.31}{0.53}

             = 2.47 M

Putting the values in freezing point equation

ΔT = 1.31 x 29.8 x 2.47

ΔT = 73.606 degrees

You might be interested in
I have science and i have a question that says : an element is a (valuable, pure , rare) substance that is not chemically combin
mote1985 [20]

Answer:

It’s true ( pure).

Explanation:

An element is defined as a pure substance that is not chemically combined with any other elements. An element comprises of mainly the sane type of atoms.

While a compound is a substance that consists of two or more elements which are chemically combined together. This is the main difference between an element and a compound.

3 0
3 years ago
Name the following ionic compounds. Use the periodic table, the table of common polyatomic ions, and
shepuryov [24]

Answer: aluminum oxide

Explanation:

4 0
2 years ago
What is the mass of a sample containing 3.5 moles of silicon atoms?
Natalija [7]
The answer is c .”98 g “
3 0
2 years ago
A substance has a mass of 360 g and a volume of 7.5 cm3. What is its density?
a_sh-v [17]
D = g / cm³

Density = mass / volume

D = 360 g / 7.5 cm³

D = 48 g/cm³

answer D

hope this helps!
7 0
3 years ago
What masses of monobasic and dibasic sodium phosphate will you use to make 250 mL of 0.1 M sodium phosphate buffer, pH = 7?
Oduvanchick [21]

Answer:

  • Mass of monobasic sodium phosphate = 1.857 g
  • Mass of dibasic sodium phosphate = 1.352 g

Explanation:

<u>The equilibrium that takes place is:</u>

H₂PO₄⁻ ↔ HPO₄⁻² + H⁺    pka= 7.21 (we know this from literature)

To solve this problem we use the Henderson–Hasselbalch (<em>H-H</em>) equation:

pH = pka + log\frac{[A^{-} ]}{[HA]}

In this case [A⁻] is [HPO₄⁻²], [HA] is [H₂PO₄⁻], pH=7.0, and pka = 7.21

If we use put data in the <em>H-H </em>equation, and solve for [HPO₄⁻²], we're left with:

7.0=7.21+log\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\ -0.21=log\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\\\10^{-0.21} =\frac{[HPO4^{-2} ]}{[H2PO4^{-} ]}\\0.616 * [H2PO4^{-}] = [HPO4^{-2}]

From the problem, we know that [HPO₄⁻²] + [H₂PO₄⁻] = 0.1 M

We replace the value of [HPO₄⁻²] in this equation:

0.616 * [H₂PO₄⁻] + [H₂PO₄⁻] = 0.1 M

1.616 * [H₂PO₄⁻] = 0.1 M

[H₂PO₄⁻] = 0.0619 M

With the value of [H₂PO₄⁻]  we can calculate [HPO₄⁻²]:

[HPO₄⁻²] + 0.0619 M = 0.1 M

[HPO₄⁻²] = 0.0381 M

With the concentrations, the volume and the molecular weights, we can calculate the masses:

  • Molecular weight of monobasic sodium phosphate (NaH₂PO₄)= 120 g/mol.
  • Molecular weight of dibasic sodium phosphate (Na₂HPO₄)= 142 g/mol.

  • mass of NaH₂PO₄ = 0.0619 M * 0.250 L * 120 g/mol = 1.857 g
  • mass of Na₂HPO₄ = 0.0381 M * 0.250 L * 142 g/mol = 1.352 g
5 0
3 years ago
Other questions:
  • A sample of hydrogen gas has an initial pressure of 2.86 atm and an initial volume of 8472 mL If the volume of the
    15·1 answer
  • Describe a structure of a ecosystem
    15·1 answer
  • 1. Use electron dot formulas to predict the formulas of the ionic compounds formed from the
    15·2 answers
  • What is earths surface made of?
    13·2 answers
  • Consider the reaction 2H2S(g)⇌2H2(g)+S2(g),Kp=2.4×10−4 (at 1073 K) A reaction mixture contains 0.111 atm of H2, 0.051 atm of S2,
    7·1 answer
  • For the following reaction, 3.70 grams of oxygen gas are mixed with excess carbon monoxide . The reaction yields 8.25 grams of c
    15·1 answer
  • Can some body please help me with this Stoichiometry stuff
    11·1 answer
  • Plz help
    14·1 answer
  • Given the balanced chemical equation for the decomposition for INO, and the rate of disappearance of INO, write the expressions
    11·1 answer
  • A molecular orbital that decreases the electron density between two nuclei is said to be ____.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!