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
Anastasy [175]
2 years ago
14

Can someone please help me please?

Chemistry
2 answers:
shepuryov [24]2 years ago
7 0

Answers:

0.77 °C·kg·mol⁻¹; 0.261 °C

Step-by-step explanation:

13. a. Boiling point elevation

The formula for boiling point elevation ΔTb is

ΔTb = Kb·b     Divide each side by b

Kb = ΔTb/b

Kb = 2.4/3.1

Kb = 0.77 °C·kg·mol⁻¹

===============

13. b. Freezing point depression

The formula for freezing point depression \Delta T_{f} is

\Delta T_{f} = \Delta K_{f} \cdot b

b = moles of solute/kilograms of solvent

b = 0.705/5.02

b = 0.1404 mol/kg

\Delta T_{f} = 1.86 \times 0.1404

\Delta T_{f} = 0.261 \textdegree \text{C}

artcher [175]2 years ago
7 0

Answer:

1) The value of the K_b is 0.07742°C/m.

2) 0.261°C is the freezing-point depression of a solution.

Explanation:

1) \Delta T_b=T_b-T

\Delta T_b=K_b\times m

\Delta T_b=iK_b\times \frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Mass of solvent in Kg}}

where,

\Delta T_b =Elevation in boiling point

K_b = boiling point constant of solvent= 3.63 °C/m

1 - van't Hoff factor (non-electrolyte solute)

m = molality

We have :  \Delta T_b=2.4^oC

m = 3.1 m

K_b=?

\Delta T_b=K_b\times m

2.4^oC=K_b\times 3.1 m

K_b=\frac{2.4 ^oC}{3.1 m}=0.07742 ^oC/m

The value of the K_b is 0.07742°C/m.

2) \Delta T_f=T-T_f

\Delta T_f=K_f\times m

Delta T_f=iK_f\times \frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{Mass of solvent in Kg}}

where,

\Delta T_f =depression in freezing point

K_f = freezing point constant of solvent= 1.86°C/m

1 - van't Hoff factor (non-electrolyte solute)

m = molality

We have , Moles of solute = 0.705 mol

Mass of solvent = 5.02 kg

molality=\frac{\text{Moles of solute }}{\text{Mas of solvent(kg)}}

m = \frac{0.705 mol}{5.02 kg}=0.1404 mol/kg

K_f=1.86^oC/m

\Delta T_f=iK_f\times m

=1\times 1.86 ^oC/m\times 0.1404 m

=0.261^oC

0.261°C is the freezing-point depression of a solution.

You might be interested in
En que epoca aprendieron a trabaja el cobre y otros metales?
g100num [7]
Maybe if you put it in english i’ll answer.. nahh jp i’m fluent
6 0
2 years ago
What are two examples of homogeneous<br>​
Andrei [34K]

Answer:

two examples are blood and soapy water.

Explanation:

7 0
2 years ago
C.) Is heating of cobalt (ii) chloride crystals a chemical change or a physical change (Imk)​
miv72 [106K]

Answer: Heating the hydrated forms of cobalt chloride reverses the reactions above, returning cobalt chloride to the blue, water-free, or anhydrous, state. Water is "liberated" in these reactions, known as dehydration reactions.

Explanation:

8 0
3 years ago
A student was conducting an experiment designed to study the law of conservation of mass. The student measured the mass of all t
never [62]
562 grams because mass can not be created or destroyed
6 0
2 years ago
How many moles of Na3PO4 are in 820. grams of it?
kotegsom [21]

Answer:Hello

D is correct

Explanation:

4 0
2 years ago
Other questions:
  • How can i prove that nascent oxygen more reactive than normal oxygen ?
    10·1 answer
  • What are at least two things people can do today to help protect Earth and reduce levels of CO2.
    12·1 answer
  • Determine the empirical formula for a compound that contains c, h and o. it contains 52.14% c and 34.73% o by mass.
    7·2 answers
  • The atomic mass of 12C is 12.000000. Multiply the atomic mass of 12C by its abundance. Report the number to 5 significant digits
    6·2 answers
  • Write the oxidation number for the following elements: for brainliest answer
    12·1 answer
  • Only someone who truly knows and understands this, please tell me if the electron configurations are right :
    15·1 answer
  • SHOW WORK
    13·1 answer
  • The substance that releases 21.2 kJ of energy when 1.42 mol of it freezes is____________
    13·1 answer
  • HCI + NaOH .-&gt; Nacl + H2O <br> what is the Mole ratio of acid to alkali ?<br>​
    11·2 answers
  • When heat is added to the substances, the atoms being to?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!