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2 years ago

When does phenolphthalein turn pink?

Chemistry

2 answers:

Art [367]2 years ago

8 0

A) in the presence of a base

Gelneren [198K]2 years ago

7 0

Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols for use in experiments.

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What are the 3 types of zeros?

kotegsom [21]

Leading zeros
Captive zeros
Trailing zeros

8 0

2 years ago

This answer please :)

Artemon [7]

Answer:

ithink it is c but i dont my ghess

Explanation:

i want to do thos for the points tbh

5 0

2 years ago

A galvanic (voltaic) cell consists of an electrode composed of chromium in a 1.0 M chromium(III) ion solution and another electr

svetlana [45]

Answer: The potential of the following electrochemical cell is 1.08 V.

Explanation:

$E^0_(Cr^{3+}/Cr)$ =-0.74V[/tex]

$E^0_(Cu^{2+}/Cu)$ =0.34V[/tex]

The element with negative reduction potential will lose electrons undergo oxidation and thus act as anode.The element with positive reduction potential will gain electrons undergo reduction and thus acts as cathode.

Here Cr undergoes oxidation by loss of electrons, thus act as anode. copper undergoes reduction by gain of electrons and thus act as cathode.

$2Cr+3Cu^{2+}\rightarrow 2Cr^{3+}+3Cu$

$E^0=E^0_{cathode}- E^0_{anode}$

Where both $E^0$ are standard reduction potentials, when concentration is 1M.

$E^0=E^0_{[Cu^{2+}/Ni]}- E^0_{[Cr^{3+}/Cr]}$

$E^0=0.34-(-0.74)=1.08V$

Thus the potential of the following electrochemical cell is 1.08 V.

6 0

2 years ago

A 17.9 mL sample of a 0.445 M aqueous hypochlorous acid solution is titrated with a 0.374 M aqueous sodium hydroxide solution. W

In-s [12.5K]

Answer:

the pH at the start of the titration is 3

4 0

2 years ago

How many moles of silver can be produced from silver nitrate from 1 mole of zinc?

jasenka [17]

Answer:

Answer: 6.5 moles of silver metal is formed in the given chemical reaction. The moles of excess reagent left are 0.55 moles.

Explanation:

To calculate the moles of silver formed and the moles of excess reagent left after the reaction, we need to balance the equation first and need to find the limiting and excess reagent.

The balanced chemical equation is:

Zn + 2AgNO3 ---> Zn (NO3)2 +2Ag

By Stoichiometry:

2 moles of Silver nitrate reacts with 1 mole of Zinc metal

So, 6.5 moles of silver nitrate will react with = 1/2 x 6.5 = 3.25 moles of zinc metal

The required amount of zinc metal is less than the given amount of zinc metal, hence, it is considered as an excess reagent.

Therefore, silver nitrate is the limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of silver nitrate produces 2 moles of silver metal

So, 6.5 moles of silver nitrate will produce = 2/2 x 6.5 = 6.5moles of silver metal.

Number of moles of excess reagent left after the completion of reaction = (3.8 - 3.25)moles = 0.55 moles

Hence, 6.5 moles of silver metal is formed in the given chemical reaction. The moles of excess reagent left are 0.55 moles.

4 0

1 year ago