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
Masja [62]
3 years ago
13

The boiling point elevation of an aqueous sucrose is found to be 0.39 Celsius. What mass of sucrose (molar mass = 342.30g/mol) w

ould be needed to dissolve in 500.0 g of water? Kb (water) = 0.513 C/m
Chemistry
1 answer:
FromTheMoon [43]3 years ago
7 0

Answer:

130 g of sucrose

Explanation:

Boiling point elevation formula → ΔT = Kb . m

ΔT = Boiling T° solution - Boiling T° pure solvent → 0.39°C

0.39°C = 0.513°C/m . M

m = 0.760 mol/kg → molality = moles of solute / 1kg of solvent

Let's determine the moles of solute → molality . kg

0.760 mol/kg. 0.5 kg = 0.380 moles

If we convert the moles to mass, we'll get the answer

0.380 mol . 342.30 g/mol = 130g

You might be interested in
6. Write a balanced equation for each reaction. You must change each word equation into a chemical equation with actual formulas
leva [86]
The answer is in the pic!

4 0
3 years ago
9.44 x 10^3 In standard form
Marta_Voda [28]
9440 is standard form.
5 0
3 years ago
A 100.0 ml sample of 0.10 m ca(oh)2 is titrated with 0.10 m hbr. determine the ph of the solution after the addition of 400.0 ml
WINSTONCH [101]
The balanced equation for the reaction is as follows;
Ca(OH)₂ + 2HBr --> CaBr₂ + 2H₂O
stoichiometry of Ca(OH)₂ to HBr is 1:2
number of Ca(OH)₂ moles reacted - 0.10 mol/L x 0.1000 L = 0.010 mol
Number of HBr moles added - 0.10 mol/L x 0.4000 = 0.040 mol 
1 mol of Ca(OH)₂ needs 2 mol of HBr for neutralisation
therefore 0.010 mol of Ca(OH)₂  needs - 0.010 x 2 = 0.020 mol of HBr to be neutralised
but 0.040 mol of HBr has been added therefore number of moles of HBr in excess - 0.040 - 0.020 = 0.020 mol 
then pH of the medium can be calculated using the excess H⁺ ions
HBr is a strong acid therefore complete ionization
[HBr] = [H⁺]
[H⁺] = 0.020 mol / (100.0 + 400.0 mL)
      = 0.020 mol / 0.5 L 
      = 0.040 mol/L
pH = -log[H⁺] 
pH = - log [0.040 M]
pH = 1.40
pH of the medium is 1.40
8 0
3 years ago
What is the function of the phytoplankton in the ocean ecosystem
Nitella [24]

Phytoplankton is a type of micro algae. This creature is similar to the other plants in the ocean biome. But what makes it special is the fact that it is the main produce in the food web. The plant is so small that it is impossible to see it with the naked eye.

ads

However, that doesn’t remove the fact that phytoplankton contains a huge amount of chlorophyll. Here are the 13 Function of the Phytoplankton in Ocean Ecosystem. Find out what makes this small plant so crucial to the ocean

7 0
3 years ago
Isoelectric point. The isoelectric point (pI) is the pH at which a molecule has no net charge. The amino acid glycine has two io
timama [110]

Answer:

pI = 6.16

Explanation:

The pI is given by the average of the pKas that are involved. In this case,

Pka of carboxylic acid was given as 2.72 and that of the Amino group was given as 9.60. the average would then be ½(2.72+9.60)

= 6.16

6 0
3 years ago
Other questions:
  • What is a chemical change?
    10·1 answer
  • Does any one have a sixth grade Ohio science fusion book
    6·1 answer
  • How is the decomposing of water a chemical change?
    12·2 answers
  • Is anyone else's brainly not working or is mine the only one that is tweaking?
    6·1 answer
  • Which of the following accurately pairs the part of an atom to its charge? A. Proton—no charge B. Neutron—positive charge C. Ele
    6·2 answers
  • Un gas a una temperatura de 38°C, tienen un volumen de 21 Lts Litros. ¿Qué volumen tendrá si la temperatura sube a 67°C?.
    14·1 answer
  • The reform reaction between steam and gaseous methane (CH4) produces "synthesis gas," a mixture of carbon monoxide gas and dihyd
    10·1 answer
  • tetrachloromethane and water can be seperated using a seperating funnel . what can be reduced from this statement
    5·1 answer
  • If 2 objects have the same density they must have the same
    14·1 answer
  • Would the plastic have a positive charge, negative charge, or no charge? *
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!