Does the amount of a substance affect the properties of a substance?

What would be the composition and ph of an ideal buffer prepared from lactic acid (ch3chohco2h), where the hydrogen atom highlig

Mashutka [201]

Answer:

$P_H =2.86$

$c=1.4\times 10^{-4}$

Explanation:

first write the equilibrium equaion ,

$C_3H_6O_3$ ⇄ $C_3H_5O_3^{-} +H^{+}$

assuming degree of dissociation $\alpha$ =1/10;

and initial concentraion of $C_3H_6O_3$ =c;

At equlibrium ;

concentration of $C_3H_6O_3 = c-c\alpha$

$[C_3H_5O_3^{-} ]= c\alpha$

$[H^{+}] = c\alpha$

$K_a = \frac{c\alpha \times c\alpha}{c-c\alpha}$

$\alpha$ is very small so $1-\alpha$ can be neglected

and equation is;

$K_a = {c\alpha \times \alpha}$

$[H^{+}] = c\alpha$ = $\frac{K_a}{\alpha}$

$P_H =- log[H^{+} ]$

$P_H =-logK_a + log\alpha$

$K_a =1.38\times10^{-4}$

$\alpha = \frac{1}{10}$

$P_H= 3.86-1$

$P_H =2.86$

composiion ;

$c=\frac{1}{\alpha} \times [H^{+}]$

$[H^{+}] =antilog(-P_H)$

$[H^{+} ] =0.0014$

$c=0.0014\times \frac{1}{10}$

$c=1.4\times 10^{-4}$

6 0

3 years ago

You have a 5-liter container with 1.30 x 1024 molecules of ammonia gas (NH3) at STP.

bogdanovich [222]

Answer:

3). 1.30 × 10^(24) molecules

Explanation:

From avogadro's law which state that equal volume of all gases at the same temperature and pressure contain the same number of molecules.

We can relate it to this question as;

V₁/n₁ = V₂/n₂

Where;

V₁ is initial volume

n₁ is initial number of molecules

V₂ is final volume

n₂ is final number of molecules

Thus at STP, we have V₁ = V₂ and as such Plugging in the relevant values gives;

5/(1.30 x 10^(24)) = 5/n₂

n₂ = 1.30 x 10^(24) molecules

6 0

2 years ago

Which of the following elements has the highest

Blizzard [7]

Because H is a non-metal, it has the highest electronegativity. Option (1) H is correct.
Hope this would help~

3 0

2 years ago

Read 2 more answers

Elemental Li and Na are prepared by electrolysis of a molten salt, whereas K, Rb, and Cs are prepared by chemical reduction.(c)

pishuonlain [190]

Calcium is used to isolate Rb from molten RbX because calcium has a smaller atomic radius than rubidium.

A chemical element's atomic radius, which is typically the average or typical distance between the nucleus's core and the outermost isolated electron, serves as a gauge for the size of an atom. There are numerous non-equivalent definitions of atomic radius since the border is not a clearly defined physical entity. Van der Waals radius, ionic radius, metallic radius, and covalent radius are the four most frequently used definitions of atomic radius. Atomic radii are typically measured in a chemically bound condition since it is challenging to isolated individual atoms in order to measure their radii individually.

Learn more about atomic radius here:

brainly.com/question/13607061

#SPJ4

4 0

1 year ago

Which of the following changes can alter the form of a substance but does not necessarily change it to an other substance?

Goshia [24]

Answer:

The physical changes can alter the form of a substance but does not necessarily change it to an other substance

Explanation:

The physical properties of matter is one that does not depend on composition.It just change the form of matter into another form with changing into composition.

Physical properties include: appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.

The three states of matter are: solid, liquid, and gas. The melting point and boiling point are related to changes of the state of matter. All matter may exist in any of three physical states of matter.

Example:

When water is boiled then it change into vapors. Now the form of water is change but its composition is same like water
When water freezes into ice, now phase are different i.e water is liquid while ice is solid but both have same composition.

8 0

2 years ago