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3 years ago

PLEASE HELP BRAINLIEST AND 15 points.

Chemistry

1 answer:

PtichkaEL [24]3 years ago

5 0

Answer:

Substance B, boiling point of 105 °C

Explanation:

Non volatile substances have high boiling points

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Calculate the ph at of a solution of sodium hypochlorite . note that hypochlorous acid is a weak acid with a of . round your ans

loris [4]

The question is incomplete, here is the complete question:

Calculate the pH at 25°C of a 0.39 M solution of sodium hypochlorite NaClO. Note that hypochlorous acid HClO is a weak acid with a pKa of 7.50. Round your answer to 1 decimal place.

Answer: The pH of the solution is 10.4

Explanation:

We are given:

Molarity of sodium hypochlorite = 0.39 M

$pK_a$ of HClO = 7.50

We know that:

$pK_a=-\log K_a$

$K_a$ of HClO = $10^{-7.50}=3.16\times 10^{-8}$

To calculate the base dissociation constant for the given acid dissociation constant, we use the equation:

$K_w=K_b\times K_a$

where,

$K_w$ = Ionic product of water = $10^{-14}$

$K_a$ = Acid dissociation constant = $3.16\times 10^{-8}$

$K_b$ = Base dissociation constant

Putting values in above equation, we get:

$10^{-14}=3.16\times 10^{-8}\times K_b\\\\K_b=\frac{10^{-14}}{3.16\times 10^{-8}}=3.16\times 10^{-7}$

The chemical equation for the reaction of hypochlorite ion with water follows:

$ClO^-+H_2O\rightarrow HClO+OH^-$

Initial: 0.39

At eqllm: 0.39-x x x

The expression of $K_b$ for above equation follows:

$K_b=\frac{[HClO][OH^-]}{[ClO^-]}$

Putting values in above equation, we get:

$3.16\times 10^{-7}=\frac{x\times x}{(0.39-x)}\\\\x=-0.00035,0.00035$

Neglecting the negative value of 'x' because concentration cannot be negative

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

$pOH=-\log[OH^-]$

We are given:

$[OH^-]=0.00035M$

Putting values in above equation, we get:

$pOH=-\log (0.00035)=3.6$

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

$pH+pOH=14\\pH=14-3.6=10.4$

Hence, the pH of the solution is 10.4

3 0

3 years ago

Help! ASAP! Please on the questions

KiRa [710]

Answer:

62.15 m (squared)

Explanation:

We know that the Area of the square is 5.5 x 4= 22

so 90 degree to 30 degree is divide by 3

so u divide 22 by 3 and get 7.3 wich is the semi circle thing

now 7.3 x 5.5 = 40.15

22 + 40.15 = 62.15 m (squared)

Look im not really sure but I think this is the answer

Please mark as brainliest

Have a great day, be safe and healthy

Thank u

8 0

3 years ago

Read 2 more answers

Find the number of mol-atom in 7.1 gr cl

marin [14]

I don’t know if this would help but my cousin said this: Molecular weight of chlorine = 71, so 7.1/71 = 0.1 mol of Cl2

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How many grams of hydrogen are produced when 125 g of iron reacts with 125 g of water?

Makovka662 [10]

13.89g hope this helps!

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A tire at 21°C has a pressure of 0.82 atm. Its temperature decreases to –3.5°C. If there is no volume change in the tire, what i

Shtirlitz [24]

Answer:

Explanation:

0.75

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