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
DerKrebs [107]
3 years ago
7

When a 18.0 mL sample of a 0.308 M aqueous hydrofluoric acid solution is titrated with a 0.361 M aqueous sodium hydroxide soluti

on, what is the pH after 23.0 mL of sodium hydroxide have been added?
Chemistry
1 answer:
sleet_krkn [62]3 years ago
4 0

Answer:

pH = 12.8

Explanation:

HF + NaOH → F⁻ + Na⁺ + H₂O

<em>1 mole of HF reacts with 1 mole of NaOH</em>

<em />

Initial moles of HF and NaOH are:

HF = 0.018L × (0.308mol / L) = 5.544x10⁻³mol HF

NaOH = 0.023L × (0.361mol / L) = 8.303x10⁻³mol NaOH

That means moles of NaOH remains after reaction are:

8.303x10⁻³mol - 5.544x10⁻³mol = <em>2.759x10⁻³moles NaOH</em>

Total volume is 18.0mL + 23.0mL = 41.0mL = 0.0410L

Molar concentration of NaOH is

2.759x10⁻³moles NaOH / 0.0410L = 0.0673M = [OH⁻]

pOH = - log [OH⁻] = 1.17

As pH = 14 - pOH

<em>pH = 12.8</em>

<em></em>

You might be interested in
Find the final equilibrium temperature when 15.0 g of milk at 13.0 degrees c is added to 148 g of coffee with a temperature of 8
user100 [1]

According to zeroth law of thermodynamics, when two objects are kept in contact, heat (energy) is transferred from one to the other until they reach the same temperature (are in thermal equilibrium). When the objects are at the same temperature there is no heat transfer.

So, at equilibrium, q_{lost}=q_{gain},  q_{lost}= q_{milk} + q_{coffee}

q=m×c×T, where q = heat energy, m = mass of a substance, c = specific heat (units J/kg∙K), T is temperature

q_{lost}= (15X13X4.19)+(148X88.3X4.19), (15+148)X4.19XT_{final}=(15X13X4.19)+(148X88.3X4.19)

T_{final}= 81.37 ° C

6 0
3 years ago
Test tubes are used mostly for _____. A. storing experimental samples B. making precise measurements of liquids C. containing ex
Annette [7]

Answer: A) Storing experimental samples

Explanation:

It is a common piece of laboratory glassware that can be made of glass or plastic and is opened at the top and closed at the bottom.

It cannot be used for measurements because there is no graduation indicating the volume.

Althought it can contain extra chemicals left over from an experiment, it is not the main proposal of the glassware that is to store samples.

It cannot be used in a microscope and the object for that is a microscope slide.

8 0
3 years ago
Fungi have eukaryotic cells (large cells with a nucleus), like animals and plants<br> True or false?
Serggg [28]
True your answer is true
8 0
3 years ago
OMG PLEASE HELP!! THIS IS IMPORTANT!!
bogdanovich [222]

Answer:

The cell membrane is protective layer surrounding a cell.

5 0
2 years ago
Read 2 more answers
HELPPPPPPPPP 35 POINTSSSSSS!!!!!
zlopas [31]

Answer:

oxidize

Explanation:

5 0
2 years ago
Other questions:
  • Which list correctly aligns the levels of organisms from the least to the most complex? A. organ → system → tissue → cell B. tis
    7·2 answers
  • Metal in period 6 group 1
    11·1 answer
  • Why do some earthquakes cause more damage than others?
    9·2 answers
  • Five hundred (500) milliliters of sodium chloride 0.9% is prescribed to be given over 4 hours using a volumetric pump. What's th
    13·1 answer
  • A student measures a mass of an 8cm3 block of brown sugar to be 19.9G. what is the density of the brown sugar?
    6·1 answer
  • How many molecules are present in 5.45 moles of NO? Use the space below to show your work.
    6·2 answers
  • Which is an appropriate layering process for a compost pile?
    11·2 answers
  • [H3O+] = 2.9 x 10-10 M<br> ph level
    15·1 answer
  • Ca(MnQ4)2 molar mass
    5·1 answer
  • Compared to an atom of C-14, an atom of C-12 has a lesser
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!