answer.
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
liraira [26]
2 years ago
5

What is the molal concentration of a solution made by dissolving 34.2 g of sucrose, c12h22o11 (molar mass 342.34 g/mol), in 125

g of water?
Chemistry
2 answers:
Anna007 [38]2 years ago
7 0
Molality is the number of moles of solute in 1 kg of solvent
number of moles of sucrose - mass of sucrose / molar mass
number of moles of sucrose - 34.2 g / 342.34 g/mol = 0.0999 mol
number of moles in 125 g of water - 0.0999 mol 
therefore number of moles in 1000 g - 0.0999 / 125 x 1000 = 0.799 mol/kg
molality of sucrose solution - 0.799 mol/kg
Alborosie2 years ago
6 0

Answer:

0.799 mol

Explanation:

Molality is the number of moles of solute in 1 kg of solvent

number of moles of sucrose - mass of sucrose / molar mass

therefore number of moles in 1000 g - 0.0999 / 125 x 1000 = 0.799 mol

Molality of sucrose solution - 0.799 mol

You might be interested in
a student adds 15 g of baking soda to 10 g of acetic acid in a beaker. a chemical reaction occurs and a gas is given off. after
Zanzabum

The chemical equation representing the reaction between baking soda and acetic acid :

NaHCO_{3}(aq)+CH_{3}COOH(aq)-->CH_{3}COONa(aq)+H_{2}O(l)+CO_{2}(g)

According to the Law of conservation of mass, the overall mass is conserved in a chemical reaction. That is total mass of reactants is equal to the mass of the products.

Given here Mass of Baking soda = 15 g

Mass of acetic acid = 10 g

Total mass of the reactants = 15 g +10 g = 25 g

After the reaction, total mass of products = 23 g

This difference in masses must be because one of product carbon dioxide is a gas, which is lost and hence the mass of products is lower than the mass of reactants. Therefore, the mass is conserved in this reaction.

7 0
2 years ago
The density of phosphorus vapor at 310 degrees celcius and 775 mmHg is 2.64g/L. what is the molecular formula of the phosphorus
lidiya [134]

Answer:

The molecular formula of the phosphorus is P4

Explanation:

<u>Step 1:</u> Data given

Density of phosphorus vapor at 310 °C and 775 mmHg = 2.64g /L

<u>Step 2: </u>Calculate the molecular weight

We assume phosphorus to be an ideal gas

So p*V = n*R*T

 ⇒ with p = the pressure of phosphorus = 775 mmHg

⇒ with V = the Volume

⇒ with n = the number of moles = mass/molecular weight

⇒ with R = ideal gas constant  = 0.08206 L*atm/K*mol

⇒ with T = the absolute temperature

p*V = m/MW *R*T

MW = mRT/PV

 ⇒ Since the volume is unknown but can be written as density = mass/volume

MW = dRT/P

MW = (2.64g/L * 0.08206 L*atm/K*mol * 583 Kelvin)/1.0197 atm

MW = 123.86 g/mol

<u>Step 3</u>: Calculate molecular formula of phosphorus

The relative atomic mass of phosphorus = 30.97 u

123.86 / 30.97 = 4

The molecular formula of the phosphorus is P4

5 0
2 years ago
One brand of vinegar has a pH of 4.5. Another brand has a pH of 5.0. The equation for the pH of a substance is pH = –log[H+], wh
grigory [225]
[H+] in first brand:
4.5 = -log([H+])
[H+] = 10^(-4.5)

[H+] in second brand:
5 = -log[H+]
[H+] = 10^(-5)

Difference = 10^(-4.5) - 10^(-5)
= 2.2 x 10⁻⁵

The answer is A.
7 0
2 years ago
Read 2 more answers
An ion has 24 protons and 19 electrons. Write the symbol for this ion.
Lerok [7]

Answer:

+5

Explanation:

it hs 5 more protons thant electrons, so it has a positive charge of 5

5 0
2 years ago
A 6.0M solution HCl is diluted to 1.0M How many milliliters of the 6.0M solution would be used to prepare 100.o mL of the dilute
Margarita [4]
Wats r is the most soluble object ever. It is dense
4 0
2 years ago
Read 2 more answers
Other questions:
  • A 55-g sample of a gaseous fuel mixture contains 0.43 mole fraction propane; the remainder of the mixture is butane. What are th
    14·1 answer
  • A cup of gold colored metal beads was measured to have a mass 425 grams. By water displacement, the volume of the beads was calc
    8·1 answer
  • Write a balanced half-reaction describing the oxidation of gaseous dihydrogen to aqueous hydrogen cations.
    12·2 answers
  • How many milliliters of 0.550 M hydriodic acid are needed to react with 25.00 mL of 0.217 M CsOH?
    14·2 answers
  • Select all the true statements. When an atom gains an electron, it becomes a cation. Anions carry a positive charge. The Cl− and
    14·1 answer
  • The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at 1.00 atm and 25°C is required for burning
    9·1 answer
  • Lastly, Snape thinks we should try one more calculation. What is the retention factor if the distance traveled by the solvent fr
    8·1 answer
  • Consider 2.4 moles of a gas contained in a 4.0 L bulb at a constant temperature of 32°C. This bulb is connected to an evacuated
    14·1 answer
  • The following questions refer to the gas-phase decomposition of ethylene chloride. C2H5Cl ® products Experiment shows that the d
    12·1 answer
  • The heat capacity of solid iron is 0.447 J/gËC. If the same quantity of energy were transferred to a 450 g chunk of iron at 20ËC
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!