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
Ymorist [56]
3 years ago
12

Calculate the molecular weight of a substance. In which the solution of this substance in the water has a concentration of 7 per

cent by weight, has a freezing point
Equal to -0.89 ° C, set Kf value of water = 1.86 ° C / m
Chemistry
1 answer:
Eduardwww [97]3 years ago
7 0

Answer : The molecular weight of a substance is 157.3 g/mol

Explanation :

As we are given that 7 % by weight that means 7 grams of solute present in 100 grams of solution.

Mass of solute = 7 g

Mass of solution = 100 g

Mass of solvent = 100 - 7 = 93 g

Formula used :  

\Delta T_f=i\times K_f\times m\\\\T_f^o-T_f=k_f\times\frac{\text{Mass of substance(solute)}\times 1000}{\text{Molar mass of substance(solute)}\times \text{Mass of water(solvent)}}

where,

\Delta T_f = change in freezing point

T_f^o = temperature of pure water = 0^oC

T_f = temperature of solution = -0.89^oC

K_f = freezing point constant of water = 1.86^oC/m

m = molality

Now put all the given values in this formula, we get

(0-(-0.89))^oC=1.86^oC/m\times \frac{7g\times 1000}{\text{Molar mass of substance(solute)}\times 93g}

\text{Molar mass of substance(solute)}=157.3g/mol

Therefore, the molecular weight of a substance is 157.3 g/mol

You might be interested in
HELP!!!
vredina [299]

Answer:

the answer is A

Explanation:

I dont really have an explanation but hope it helps

5 0
2 years ago
Read 2 more answers
The primary method in which two connected objects transfer energy by heat flow is _____.
swat32
 Conduction is heat tranfer through physical contact. Hope this helps. :)
7 0
3 years ago
Read 2 more answers
What is the molarity of a solution containing 501mL with 35g NaCl
Vesna [10]

Answer:

Data:

mass of solute: 35g of NaCl

m.mass of solute: 58g/mol

volume of solution: 501mL

Molarity=?

Explanation:

501ml = 0.5dm3

M= g of solute/m.mass of solute*vol of solution

M= 35/58*0.5

M=1.20

6 0
3 years ago
What are two ways in which density has practical importance?
Marta_Voda [28]
<span>density is how much matter is packed into one area. so the higher density the more likely it is to be heavier. for example, cork has a very low density and iron has a higher density.</span>
6 0
3 years ago
The sum of the number of proteins and neutrons in an atoms nucleus is its __________ ___________.
otez555 [7]

Answer:

Mass Number

Explanation:

In nuclear physics, the sum of the numbers of protons and neutrons present in the nucleus of an atom.

Please vote brainliest!

8 0
2 years ago
Read 2 more answers
Other questions:
  • How much solute (in mL) would you need to add to solvent in order to create 825 mL of a final solution that is 21% solute by vol
    7·1 answer
  • what is the volume of 24.0 g of oxygen gas at stp? i need to show work and i just cant get it. please help?
    15·1 answer
  • An experimental set up involves a cell with pumps that maintain high K+ and Cl- concentrations outside of the cell, and high Na+
    5·1 answer
  • The reform reaction between steam and gaseous methane (CH4) produces "synthesis gas," a mixture of carbon monoxide gas and dihyd
    11·1 answer
  • Out of the following, which has the least amount of mass? A) protons B) none of the above C) electrons D) neutrons
    11·1 answer
  • Why might it be important to test one variable at a time when doing an experiment?
    6·1 answer
  • The rate of this reaction is markedly increased if a small amount of sodium iodide is added to the reaction mixture. The sodium
    11·1 answer
  • Select the set of coefficients that would balance the following equation:
    11·1 answer
  • Type the correct answer in the box.
    7·1 answer
  • The passage below describes an experiment. Read the passage and then follow the instructions below.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!