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
mariarad [96]
3 years ago
9

how many moles of a nonvolatile, nonelectrolyte solute are required to lower the freezing point of 1000 grams of water by 5.58

Chemistry
1 answer:
Ivan3 years ago
5 0

Answer:

Explanation:

Using freezing point depression formula,

ΔTemp.f = Kf * b * i

Where,

ΔTemp.f = temp.f(pure solvent) - temp.f(solution)

b = molality

i = van't Hoff factor

Kf = cryoscopic constant

= 1.86°C/m for water

= (0 - (-5.58))/1.86

= 3.00 mol/kg

Assume 1 kg of water(solvent)

= (3.00 x 1)

= 3.00 mol.

You might be interested in
For the reaction: CH3NH2(aq) + H2O(aq) ⇌ CH3NH3 +(aq) + OH- Determine the change in the pH (ΔpH) for the addition of 6.7 M CH3NH
Korolek [52]

Answer:

The change in the pH (ΔpH) is 2,17

Explanation:

The reaction:

CH₃NH₂(aq) + H₂O(aq) ⇌ CH₃NH₃⁺(aq) + OH⁻

kb = \frac{[OH^{-}][CH_{3}NH_{3}^+]}{[CH_{3}NH_{2}]} <em>(1)</em>

In equilibrium, a solution of CH₃NH₂ 4,7M produces:

[CH₃NH₂] = 4,7 - x

[CH₃NH₃⁺] = x

[OH⁻] = x

Replacing in (1):

4,38x10^{-4} = \frac{x^2}{4,7-x}

x² + 4,38x10⁻⁴x - 2,0586x10⁻³ = 0

The solutions are:

x = -0,0456 No physical sense. There are not negative concentrations.

x = 0,04515 Real answer.

The concentration of [OH⁻] is 0,04515 M.

As pOH = -log [OH⁻] And pH+pOH = 14. The pH of this solution is:

<em>pH = 12,65</em>

The addition of 6,7M produce this changes in concentrations:

[CH₃NH₂] = 4,656 + x

[CH₃NH₃⁺] = 6,74515 - x

[OH⁻] = 0,04515 - x

Replacing in (1) you will obtain:

x² - 6,7907x + 0,3025 = 0

Solving for x:

x = 6,74586 No physical sense

x = 0,04484 Real answer.

Thus, [OH⁻] = 0,04515 - 0,044842 = 3,08x10⁻⁴M

pOH = 3,51.

<em>pH = 10,49</em>

Thus ΔpH is 12,65 - 10,49 = <em>2,16 ≈ 2,17</em>

I hope it helps!

4 0
3 years ago
Can someone please help me with these!!!!
Elza [17]

Answer:

17)A. Solids

18) A. Frequently collide with each other and with surface of ballon

19) D. Particles are smaller at lower pressure.

6 0
3 years ago
Iron iii chloride ammonium hydroxide balanced equation, complete ionic equation, net ionic equation
Vladimir [108]
Iron III Chloride has a chemical formula of FeCl₃, while ammonium hydroxide has a chemical formula of NH₄OH. 

The <em>balanced equation</em> would be:

FeCl₃ (aq) + 3 NH₄OH (aq) → Fe(OH)₃ (s) + 3 NH₄Cl (aq)
The precipitate is Fe(OH)₃ or iron iii hydroxide.

To find the <em>complete ionic equation</em>, dissociate the compounds in aqueous phases into their ionic forms:

Fe³⁺ + Cl⁻ + NH₄⁺ + 3 OH⁻ -->  Fe(OH)₃(s) + NH₄⁺ + Cl⁻ 

To find the <em>net ionic equation</em>, cancel out like ions that appear both in the reactant and product side:

Fe³⁺ +  3 OH⁻ -->  Fe(OH)₃


4 0
3 years ago
If 20.0 g of NaOH is added to 0.750 L of 1.00 M Cd(NO₃)₂, how many grams of Cd(OH)₂ will be formed in the following precipitatio
bulgar [2K]

Answer:

m_{Cd(OH)_2}=36.6 gCd(OH)_2

Explanation:

Hello.

In this case, for the given chemical reaction, in order to compute the grams of cadmium hydroxide that would be yielded, we must first identify the limiting reactant by computing the yielded moles of that same product, by 20.0 grams of NaOH (molar mass = 40 g/mol) and by 0.750 L of the 1.00-M solution of cadmium nitrate as shown below considering the 1:2:1 mole ratios respectively:

n_{Cd(OH)_2}^{by\ NaOH}=20.0gNaOH*\frac{1molNaOH}{40gNaOH} *\frac{1molCd(OH)_2}{2molNaOH} =0.25molCd(OH)_2\\\\n_{Cd(OH)_2}^{by\ Cd(NO_3)_2}=0.750L*1.00\frac{molCd(NO_3)_2}{L}*\frac{1molCd(OH)_2}{1molCd(NO_3)_2}  =0.75molCd(OH)_2

Thus, since 20.0 grams of NaOH yielded less of moles of cadmium hydroxide, NaOH is the limiting reactant, therefore the mass of cadmium hydroxide (molar mass = 146.4 g/mol) is:

m_{Cd(OH)_2}=0.25molCd(OH)_2*\frac{146.4gCd(OH)_2}{1molCd(OH)_2} \\\\m_{Cd(OH)_2}=36.6 gCd(OH)_2

Best regards.

4 0
3 years ago
During the daytime, wind blows off of the __________________ because that material takes ___________ time to get warm, creating
Butoxors [25]

Answer: sea, more

I hope this helps

5 0
2 years ago
Other questions:
  • How many structural isomers are possible for compounds with a molecular formula c4h10?
    11·1 answer
  • Water intoxication occurs when
    7·2 answers
  • Predidt the direction and the relative value of the dipole moment of the following bond: C-Cl
    14·1 answer
  • How many grams of salt are in 5 L of a solution with a concentration of 3 g/L
    8·1 answer
  • How many grams of aluminum are required to give a total dislocation length of 3,000 miles (enough to stretch from New York City
    9·1 answer
  • Why isn't every point exactly on the 'best fit line'? Give a reason and explain
    7·1 answer
  • Where does cellular respiration occur?
    15·1 answer
  • Which electron configuration represents the electrons of an atom in an excited state?
    13·1 answer
  • In a galvanic cell, electrons are transferred from one half cell to the other as the redox reaction progresses. what happens in
    8·1 answer
  • Given 50g and 27ml find density
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!