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
Readme [11.4K]
3 years ago
6

A student who is performing this experiment pours an 8.50 mL sample of the saturated borax solution into a 10 mL graduated cylin

der after the borax solution had cooled to a certain temperature T. The student rinses the sample into a small beaker using distilled water, and then titrates the solution with a 0.500 M HCl solution. 12.00 mL of the HCl solution is needed to reach the endpoint of the titration.
Calculate the value of Ksp for borax at temperature T.
Chemistry
1 answer:
gtnhenbr [62]3 years ago
8 0

Answer:

ksp = 0,176

Explanation:

The borax (Na₂borate) in water is in equilibrium, thus:

Na₂borate(s) ⇄ borate²⁻(aq) + 2Na⁺(aq)

<em>When you add just borax, the moles of Na²⁺ are twice the moles of borate²⁻, that means 2borate²⁻=Na⁺ </em><em>(1)</em>

The ksp is defined as:

<em>ksp = [borate²⁻] [Na⁺]²</em>

Then, borate²⁻(B₄O₇²⁻) reacts with HCl thus:

B₄O₇²⁻ + 2HCl + 5H₂O → 4H₃BO₃ + 2Cl⁻

The moles of HCl that reacts with B₄O₇²⁻ are:

0,500M×0,01200L = 6,00x10⁻³ mol of HCl

As two moles of HCl react with 1 mol of B₄O₇²⁻, the moles of B₄O₇²⁻ are:

6,00x10⁻³ mol of HCl×\frac{1molB_{4}O_{7}^{2-}}{2molHCl} = <em>3,00x10⁻³ mol of B₄O₇²⁻</em>

For (1), moles of Na⁺ are <em>3,00x10⁻³ mol ×2 = 6,00x10⁻³ mol of Na⁺</em>

The [borate²⁻] is <em>3,00x10⁻³ mol of B₄O₇²⁻/0,00850L = </em><em>0,353M</em>

And [Na⁺] is <em>6,00x10⁻³ mol of Na⁺ / 0,00850L = </em>0,706M

Replacing in the expression of ksp:

ksp = [0,353] [0,706]²

<em>ksp = 0,176</em>

<em></em>

I hope it helps!

You might be interested in
Which of the following is soluble in water? <br>1-glycerin <br>2-sand<br>3-iron filing<br>4-oil​
sineoko [7]

Answer:

1-glycerin

Explanation:

Hope it helps! :)

4 0
3 years ago
Read 2 more answers
Draw the organic product of the following nucleophilic substitution reaction. Include all hydrogens atoms.
Sunny_sXe [5.5K]
<span>Answer: CH3-CH2-0-CH2-CH3 that is diethyl ether mechanism is SN2</span>
8 0
3 years ago
A student heats a liquid on a burner. What happens to the portion of liquid that first begins to warm?
Natalija [7]
I believe it becomes less dense, bc when you heat something it’s molecules spread further apart.
8 0
3 years ago
Read 2 more answers
Amoxicillin Suspension 125 mg/ 5 ml is 125 mg of Amoxicillin per 5 ml of suspension is an example of weight to ________.
kkurt [141]

Answer : Amoxicillin Suspension 125 mg/ 5 ml is 125 mg of Amoxicillin per 5 ml of suspension is an example of weight to volume.

Explanation :

Weight by volume (w/v) means that the mass of solute present in 100 mL volume of solution.

Weight by weight (w/w) means that the mass of solute present in 100 gram of solution.

Volume by volume (v/v) means that the volume of solute present in 100 mL volume of solution.

As per question, amoxicillin suspension is, 125 mg/ 5 ml that means 125 mg of Amoxicillin present in 5 mL of suspension. So, it is an example of weight to volume.

Hence, it is an example of weight to volume.

8 0
3 years ago
Draw the structure of the compound identified by the following simulated 1H and 13C NMR spectra. The molecular formula of the co
Luba_88 [7]

Answer:  4-allylanisole

Explanation: The doublets behind the 7 ppm belongs to the

para-substituted benzene ring. The three single-proton multi-plets around 5−6 ppm predicts that there has to be a single subsituted alkene group

A single plus a doublet around 3-4 ppm belongs to CH3 and CH2 Groups as they could be attached to the subsituted alkene group.

Moreover the interpretation of the NMR  that there is no peak with a higher intensity for >180 ppm represents an absence of Carbonyl group.

The Predicted Number is attached from a chemical database along with their peaks information

6 0
3 years ago
Other questions:
  • Is 4Na a molecule or an atom
    8·1 answer
  • What do oxidation reactions produce during the electrolysis of water?
    7·2 answers
  • The darkest part of the moon’s shadow is called the penumbra?
    12·2 answers
  • Use the E0 values of the following elements: Zn, Cu, Pb, and Al. Which element is the most active reducing agent?
    5·1 answer
  • Which of the following is a correct definition of the term rectification? 
    11·1 answer
  • 1. What is the main difference between a nuclear power plant and a coal burning power plant?
    7·1 answer
  • Which of these forces is acting on a baseball sitting on level ground? A. applied force B. frictional force C. gravitational for
    8·2 answers
  • HELP PLEASEEE :)) ILL GIVE BRAINLIEST! EXPLAIN YOUR ANSWER
    11·1 answer
  • The molecular mass of air, at standard pressure and temperature, is approximately 28.97 g/mol. Calculate the mass of 3.33 moles
    10·1 answer
  • When drinking water, how soon does it reach the bladder.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!