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3 years ago

Heat flows from________substances.

Chemistry

2 answers:

Sonja [21]3 years ago

8 0

conducting

HOPE THIS WILL HELP U

Andrews [41]3 years ago

6 0

hotter substnces............

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A chemist titrates of a hypochlorous acid solution with solution at . Calculate the pH at equivalence. The of hypochlorous acid

const2013 [10]

The question is incomplete, here is the complete question:

A chemist titrates 110.0 mL of a 0.2412 M hypochlorous acid (HCIO) solution with 0.0613 M NaOH solution at 25°C. Calculate the pH at equivalence. The pKa of hypochlorous acid is 7.50. Round your answer to 2 decimal places

Answer: The pH of the solution is 10.09

Explanation:

To calculate the volume of base, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HClO$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=1\\M_1=0.2412M\\V_1=110.0mL\\n_2=1\\M_2=0.0613M\\V_2=?mL$

Putting values in above equation, we get:

$1\times 0.2412\times 110.0=1\times 0.0613\times V_2\\\\V_2=\frac{1\times 0.2412\times 110.0}{1\times 0.0613}=432.8mL$

At equivalence, the number of moles of acid is equal to the number of moles of base. Also, the moles of salt which is NaClO will also be the same.

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$ .....(1)

For HClO:

Molarity of HClO solution = 0.2412 M

Volume of solution = 110.0 mL

Putting values in equation 1, we get:

$0.2412M=\frac{\text{Moles of HClO}\times 1000}{110}\\\\\text{Moles of HClO}=\frac{(0.2412\times 110)}{1000}=0.026532mol$

For NaClO:

Moles of NaClO = 0.026532 moles

Volume of solution = [432.8 + 110] mL = 542.8 mL

Putting values in above equation, we get:

$\text{Molarity of NaClO}=\frac{0.026532\times 1000}{542.8}=0.0489M$

To calculate the pH of the solution, we use the equation:

$pH=7+\frac{1}{2}[pK_a+\log C]$

where,

$pK_a$ = negative logarithm of weak acid which is hypochlorous acid = 7.50

C = concentration of the salt = 0.0489 M

Putting values in above equation, we get:

$pH=7+\frac{1}{2}[7.50+\log (0.0489)]\\\\pH=7+3.09=10.09$

Hence, the pH of the solution is 10.09

4 0

3 years ago

Which missing item would complete this beta decay reaction?

madam [21]

Answer:

<h3>The answer is option A.</h3>

Hope this helps you

8 0

3 years ago

. What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?

erica [24]

Moles He = 7.83 x 10^24 / 6.02 x 10^23 =13.0

mass He = 13.0 mol x 4.00 g/mol = 52.0 g

6 0

3 years ago

What is physical weathering? (1 point)

steposvetlana [31]

Answer:

well physical weathering is the process of a element or acts of water rock or other items that take its toll on items

Explanation:

so i would,WITH CONFIDENCE C.

5 0

2 years ago

Read 2 more answers

Are the following statements true or false? (a) Formal charges represent an actual separation of charges. true false (b) ΔH o rx

katrin [286]

Answer:

Explanation:

A) Formal charges represent an actual separation of charges.(FALSE)

(B) ΔHo rxn can be estimated from the bond enthalpies of reactants and products.(TRUE)

C)All second-period elements obey the octet rule in their compounds(FALSE).

(D)The resonance structures of a molecule can be separated from one another in the laboratory.(FALSE)

Bond enthalpy which is also reffered to as bond energy is the amount of energy that is required to break one mole of a bond.

taking the single bond between Oxygen and Hydrogen into considerationthe bond energy between their single bond is 463 kJ/mol.

formal charge is used for the comparison of the number of electrons present around an atom in a particular molecule with the number of electrons present around a neutral

3 0

2 years ago