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
anygoal [31]
3 years ago
10

A 29.2 mL sample of a 0.458 M aqueous hydrofluoric acid solution is titrated with a 0.337 M aqueous sodium hydroxide solution. W

hat is the pH at the start of the titration, before any sodium hydroxide has been added
Chemistry
1 answer:
Svetach [21]3 years ago
4 0

Answer:

3.51

Explanation:

Before any sodium hydroxide has been added, the pH is that of the aqueous hydrofluoric acid solution.

HF is a weak acid that dissociates according to the following equation.

HF(aq) ⇄ H⁺(aq) + F⁻(aq)      Ka = 6.76 × 10⁻⁴

We can find [H⁺] using the following expression.

[H⁺] = √(Ca × Ka)

where

Ca: concentration of the acid

Ka: acid dissociation constant

[H⁺] = √(Ca × Ka)

[H⁺] = √(0.458 × 6.76 × 10⁻⁴)

[H⁺] = 3.10 × 10⁻⁴ M

The pH is:

pH = -log [H⁺]

pH = -log 3.10 × 10⁻⁴ = 3.51

You might be interested in
Which of the following provides the most evidence for the theory of plate tectonics?
zhenek [66]

Answer:

i dunno

Explanation:

m xlaklXMLXL

5 0
3 years ago
There is a 50 g sample of ra-229. It has a half-life of 4 minutes.how much will be left after 12 minutes? a. 3.13 g b. 6.25 g c.
polet [3.4K]

It's B. 6.25

first divide 50/2

then divide 25/2

after that divide 12.5/2

Then you get 6.25

Hope it helps!

3 0
3 years ago
Given the standard heats of reaction
ANTONII [103]

Answer:

Explanation:

M(s) → M (g ) + 20.1 kJ --- ( 1 )

X₂ ( g ) → 2X (g ) + 327.3 kJ ---- ( 2 )

M( s) + 2 X₂(g) → M X₄ (g ) - 98.7 kJ ----- ( 3 )

( 3 ) - 2 x ( 2 ) - ( 1 )

M( s) + 2 X₂(g) - 2 X₂ ( g ) - M(s)  → M X₄ (g ) - 98.7 kJ -  2 [ 2X (g ) + 327.3 kJ ] - M (g ) - 20.1 kJ

0 = M X₄ (g ) - 4 X (g ) - M (g ) - 773.4 kJ

4 X (g ) +  M (g ) =  M X₄ (g ) - 773.4kJ

heat of formation of M X₄ (g ) is - 773.4 kJ

Bond energy of one M - X bond =  773.4 / 4 =  193.4 kJ / mole

6 0
3 years ago
Select all that apply.
sergeinik [125]
ANSWER:

mL, g, m


MARK ME BRAINLIEST PLEASE
8 0
3 years ago
Which of the following abilities is NOT a physical property of matter?
Morgarella [4.7K]

Answer:

Ability to react chemically with other substances is not a physical property.

Explanation:

The ability to dissolve in other substance can be both physical and chemical property.

It depend upon the type of solute, solvent and reaction between them.

For example, if NaCl is dissolved in water it gives sodium and chloride ions which are behaving different from the original compound. it will be chemical change but if water is evaporated it will give back sodium chloride and than it will be a physical change.

But if dissolved substances make the mixture not compound it will than a physical change, and solubility will consider a physical property.

Physical properties:

The properties which are not associated with change in chemical composition are called physical properties.                                                                                          

Example

Density, color, hardness, conductance, melting point, boiling points all  are physical properties.

Chemical properties:

The properties which are associated with change in chemical composition are called chemical properties.        

Example:

Toxicity, flammability, heat of combustion etc.

Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood

The reaction of Hydrogen and oxygen:

H 2 (g)  + O 2  (g) -------------------------------------> 2H 2O  (l)

8 0
3 years ago
Other questions:
  • Which of these is the best argument for switching from combustion-powered cars to fuel cell cars in order to help the environmen
    15·1 answer
  • Which usually have no luster metals, nonmetals and metalloids
    10·2 answers
  • In a voltaic cell, where does the reduction take place?
    6·1 answer
  • How many moles are in 5.34 x 10*21 particles of Nitrogen?
    15·1 answer
  • An aqueous solution of ________ will produce a neutral solution. An aqueous solution of ________ will produce a neutral solution
    15·1 answer
  • Captures and stores energy for the cell by the process of photosynthesis
    13·1 answer
  • Baking soda has a pH of 8. Its a(n) _________ substance
    9·1 answer
  • Decay chains exist because
    11·1 answer
  • Energy that is stored due to an object's height above the ground is __
    14·1 answer
  • In a chemical reaction, the mass of the reactants is 13.3 grams. Which of the following could represent the mass of the products
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!