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
slamgirl [31]
3 years ago
11

Calculate the molality for each of the following solutions. Then, calculate the freezing-point depression ΔTF = iKFcm produced b

y each of the salts. (Assume the density of water is 1.00 g/mL and KF = 1.86°C/m.) (a) 3.2 M NaCl (Assume the density of the solution is 1.00 g/mL.) Cm = WebAssign will check your answer for the correct number of significant figures. 3.9 Correct: Your answer is correct. m ΔTF = WebAssign will check your answer for the correct number of significant figures.14.5 Incorrect: Your answer is incorrect. Check the number of significant figures.°C (b) 24 g of KCl in 1.5 L of water Cm = WebAssign will check your answer for the correct number of significant figures. 0.21 Correct: Your answer is correct. m ΔTF = WebAssign will check your answer for the correct number of significant figures. 0.78 Incorrect: Your answer is incorrect. °C
Chemistry
1 answer:
zlopas [31]3 years ago
7 0

Answer:

a) Cm= 3.9 m  ; ΔTf= 14.51 ºC

b) Cm= 0.21 m ; ΔTf= 0.79ºC

Explanation:

In order to solve the problems, we have to remember that the molality (m) of a solution is equal to moles of solute in 1 kg of solvent.

m= mol solute/kg solvent

a) In this case we have molarity, which is moles of solute in 1 liter of solution. We have to know how many kg of solvent (water) we have in 1 L of solution.

3.2 M NaCl= 3.2 mol NaCl/ 1 L solution

1 L solution= 1000 ml solution x 1.00 g/ml= 1000 g

A solution is composed by solute (NaCl) + solvent, so:

1000 g solution = g NaCl + g solvent

g NaCl= 3.2 mol NaCl x 58.44 g/mol= 187 g NaCl

g solvent= 1000 g - 187 g NaCl= 813 g= 0.813 kg

Cm= 3.2 g NaCl/0.813 kg solvent= 3.9 m

NaCl is an electrolyte and it dissociates in water in two ions: Na⁺ anc Cl⁻, si the van't Hoff factor (i) is 2.

ΔTf= i x KF x Cm= 2 x 1.86ºC/m x 3.9 m= 14.51ºC

b) In this case we have 24 g of solute in 1.5 L of solvent. We have to convert the liters of solvent to kg, and to convert the mass of solute to mol by using the molecular weight of KCl (74.55 g/mol):

24 g KCl x 1 mol KCl/74.55 g= 0.32 mol

1.5 L solvent= 1500 g solvent x 1.00 g/ml= 1500 g = 1.5 kg

Cm= 0.32 g KCl/1.5 kg solvent= 0.21 m

KCl is an electrolyte and when it dissolves in water, it dissociates in 2 ions: K⁺ and Cl⁻. For this, van't Hoff factor (i) is equal to 2.

ΔTf= i x KF x Cm= 2 x 1.86ºC x 0.21 m= 0.79ºC

You might be interested in
Brainly is so boring like upgrade it to be better or something
Nikitich [7]

Answer:

ya same here i hope so btw

7 0
3 years ago
Why is it correct to say seawater is a mixture.
ZanzabumX [31]
It's a mixture of H2O + a soluble substance like, salt.
7 0
3 years ago
Read 2 more answers
Bromine has a density of 3.10g/cm3. If you have 50.0 ML of bromine, how many grams do you have?
Zanzabum

Answer:

The answer is

<h2>155 g</h2>

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

<h3>mass = Density × volume</h3>

From the question

volume of bromine = 50 mL

density = 3.10 g/cm³

It's mass is

mass = 50 × 3.10

We have the final answer as

<h3>155 g</h3>

Hope this<u> </u>helps you

5 0
3 years ago
Read 2 more answers
What is another name for the representative elements?
jeka94

Answer:

Group A elements or the main group

Another name for the representative elements are  the Group A elements or the main group elements

Explanation:

6 0
3 years ago
Read 2 more answers
6.(01.05 LC) Which states of matter change shape when moved?(2 points) Gases and solids Liquids and gases Liquids, solids, and g
Mrrafil [7]

Answer:Gases and solids , Solids and liquids​

Explanation:

A solid has a definite shape while liquids and gases take the shape of the container in which they are found .

Hence when a substance changes it's state from gas to solid or solid to liquid, it's shape automatically changes as explained above.

3 0
3 years ago
Other questions:
  • 3. longitude is measured in degrees, hours, and seconds. a. true b. false
    10·1 answer
  • What elements react the most? Like have the most reactivity.
    12·1 answer
  • Instructions: Select the correct answer.
    12·1 answer
  • Be sure to answer all parts. What is the effect of each of the following on the volume of 1 mol of an ideal gas? (a) The pressur
    13·1 answer
  • One of the ingredients used to make bread is yeast, a type of microorganism. This may seem odd, to use a microorganism as an ing
    11·2 answers
  • Oil and fat containing food items are flushed with nitrogen. Why?
    12·2 answers
  • PLEASE HELP DUE IN 30 MINUTES NO LINKS PLEASE ​
    15·1 answer
  • 1) h2+o2 -&gt; h2o<br><br> does equation 1 follow the law of conservation of mass? how can you tell?
    10·1 answer
  • 4. Based on their placement on the periodic table, which of the following is more
    14·1 answer
  • How do you make a experiment for ions​
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!