All categories

3 years ago

Is it possible for the equivalence point of a titration to not be at pH 7? Explain your answer.

2 answers:

5 0

<span>The reason it will be 7 for some titrations is that when you titrates a strong acid with a strong base for example HCl and NaOH the salt formed is conjugate base of strong acid and will be a very weak base
That means that it cannot produce any OH^-1 and all the H+ has been converted to water.The only source of H+ or OH is water with a Ka of 10^-14 so the pH = -log [H+]=-log 10^-7 = 7
second reason is
When you titrates a weak acid with strong base at equivalence point
only a water solution of the conjugate base exists

CH3COOH + NaOH ----- Na+ CH3COO^-1 + H2O
Since the conjugate base is the conjugate base of a weak acid it will hydrolyze in water like so
for instance Na+ CH3COO^-1 + HCl---- CH3COOH + NaCl the equivalence point will be way BELOW 7 and in the case of above will be less than 5. So pH of 7 at equivalence point is only reached in strong acid strong base titrations.
hope this helps</span>

DENIUS [597]3 years ago

3 0

PH is 7 in case the strength of the acid and base are the same ( i.e. either weak or strong). In case of strong acid weak base or weak acid strong base titrations, buffer solutions can be formed which result in a pH other than 7

You might be interested in

In which direction does the wind blow from during a sea breeze

Nadusha1986 [10]

Answer:

Sea breeze moves from the areas of higher pressure on the water in the direction of the areas of lower pressure on land.

Explanation:

Sea breeze moves from the areas of higher pressure on the water in the direction of the areas of lower pressure on land. Whereas, land breeze blows from the areas of higher pressure on land to the areas of lower pressure on water.

3 0

2 years ago

Using the balanced equation for the combustion of ethane: 2C2H6 + 7O2 → 4CO2 + 6H2O, how many moles of O2 needed to produce 12 m

pickupchik [31]

Answer:

14 moles of oxygen needed to produce 12 moles of H2O.

Explanation:

We are given that balance eqaution

$2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O$

We have to find number of moles of O2 needed to produce 12 moles of H2O.

From given equation

We can see that

6 moles of H2O produced by Oxygen =7 moles

1 mole of H2O produced by Oxygen= $\frac{7}{6}$ moles

12 moles of H2O produced by Oxygen= $\frac{7}{6}\times 12$ moles

12 moles of H2O produced by Oxygen= $7\times 2$ moles

12 moles of H2O produced by Oxygen=14 moles

Hence, 14 moles of oxygen needed to produce 12 moles of H2O.

3 0

2 years ago

Answer questions a-c about the Bronsted acid-base reaction below using the identifying letters A-D below each structure. The pKa

GuDViN [60]

Answer:

a H2CO3 b HCO3- and c H+ and HCO3-

Explanation:

As the pKa value of phenol is more than that of carbonic acid(H2CO3), the carbonic acid will have high Ka value than that of phenol.

The acid that contain high Ka value act as stong acid.From that point of view H2CO3 is a strong acid than phenol as the Ka value of carbonic acid is greater than that of phenol.

The conjugate base of H2CO3 is bicarbonate ion(HCO3-)

c The species that predorminates at equilibrium are H+ and HCO3-

8 0

2 years ago

What do chemical and physical change have in common?

gtnhenbr [62]

Explanation:

The similarities between chemical and physical changes include change in state of matter and both process involve change in energy.

Chemical changes of a substance results in the formation of entirely new substances. These changes are not reversible.

Physical changes results in the change of the state of the substance which can be reversed.

However, both chemical and physical changes results in change of state of matter and both process results in change in energy.

Thus, we can conclude that the similarities between chemical and physical changes include change in state of matter and both process involve change in energy.

(it's alre answered but here it again 'NOTE: not my answer')

3 0

1 year ago

Does acid rain make new substances? Construct an argument that uses data from this investigation as evidence for your claim.

Yuri [45]

Answer:

Acid rain, like all acids, generates dissolution of chemical compounds, and reacts together with bases to be able to carry out oxide reduction reactions, which by deduction is very likely to form new substances as a result of the dissolution or acid erosion caused.

Explanation:

Acid rain is more likely to occur in large cities or large sources of pollution, since the excess of carbon dioxide in the atmosphere causes it to increase its partial pressure in a condensed way in the clouds, this is how then this cloud when being loaded with water and then generating the rain drags these masses of condensed carbon dioxide in the form of acid rain.

The degree of acidity is directly proportional to the amount of partial pressure of carbon dioxide in the atmosphere.

5 0

2 years ago