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2 years ago

Chemistry help!

Chemistry

1 answer:

Norma-Jean [14]2 years ago

3 0

Refer to the attachment.

Hope this helps you...

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True or false in a chemical reaction some of the atoms will be changed into different type of atoms

Anika [276]

Answer:

It's false

Explanation:

7 0

2 years ago

A buffer solution contains 0.496 M hydrocyanic acid and 0.399 M sodium cyanide . If 0.0461 moles of sodium hydroxide are added t

pochemuha

Answer : The pH of the solution is, 9.63

Explanation : Given,

The dissociation constant for HCN = $pK_a=9.31$

First we have to calculate the moles of HCN and NaCN.

$\text{Moles of HCN}=\text{Concentration of HCN}\times \text{Volume of solution}=0.496M\times 0.225L=0.1116mole$

and,

$\text{Moles of NaCN}=\text{Concentration of NaCN}\times \text{Volume of solution}=0.399M\times 0.225L=0.08978mole$

The balanced chemical reaction is:

$HCN+NaOH\rightarrow NaCN+H_2O$

Initial moles 0.1116 0.0461 0.08978

At eqm. (0.1116-0.0461) 0 (0.08978+0.0461)

0.0655 0.1359

Now we have to calculate the pH of the solution.

Using Henderson Hesselbach equation :

$pH=pK_a+\log \frac{[Salt]}{[Acid]}$

Now put all the given values in this expression, we get:

$pH=9.31+\log (\frac{0.1359}{0.0655})$

$pH=9.63$

Therefore, the pH of the solution is, 9.63

4 0

3 years ago

A beaker is filled to the 500 mL mark with alcohol. What increase in volume (in mL) does the beaker contain when the temperature

Aliun [14]

Answer:

"1.4 mL" is the appropriate solution.

Explanation:

According to the question,

$v_0=500$
$\alpha =1.12\times 10^{-4}$
$\Delta \epsilon = 25$

Now,

Increase in volume will be:

⇒ $\Delta V = \alpha\times v_0\times \Delta \epsilon$

By putting the given values, we get

$=1.12\times 10^{-4}\times 500\times 25$

$=1.12\times 10^{-4}\times 12500$

$=1.4 \ mL$

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3 years ago

Which of the following is a physical property of a substance?

vaieri [72.5K]

B boiling point https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Map%3A_Introductory_Chemistry_(Tro)/03%3A_Matter_and_Energy/3.05%3A_Differences_in_Matter%3A_Physical_and_Chemical_Properties#Summary

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2 years ago

Which is an example of a bioresource used to build a home?

lutik1710 [3]

The answer should be A.
Hope this helps :-)

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2 years ago