Ask question

Ask question

All categories

3 years ago

7

Match each statements with the state of matter it describes?

1 answer:

Len [333]3 years ago

5 0

Answer:

Solid liquids , plasma gas

Explanation:

It retains its shape regardless of the shape of the container

You might be interested in

The line of longitude used as the origin in a system of coordinates

3241004551 [841]

Yup, that is correct.

7 0

3 years ago

Aspirin (acetylsalicylic acid, C9H8O4) is a weak monoprotic acid. To determine its acid-dissociation constant, a student dissolv

Triss [41]

Answer:

1. $3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

2. $5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

Explanation:

1.

The $pH$ value of Aspirin solution = 2.62

$pH=-\log[H^+]$

$[H^+]=10^{-2.62}=0.00240 M$

Moles of s asprin = $\frac{2.00 g}{180 g/mol}=0.01111 mol$

Volume of the solution = 0.600 L

The initial concentration of Aspirin = c = $\frac{0.01111 mol}{0.600 L}=0.0185 M$

$HAs\rightleftharpoons As^-+H^+$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_a=\frac{[As^-][H^+]}{[HAs]}$ :

$K_a=\frac{x\times x }{(c-x)}$

$=\frac{0.00240 M\times 0.00240 M}{(0.0185-0.00240 )}$

$K_a=3.57\times 10^{-4}$

$3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

2.

The $pH$ value of ethylamine = 11.87

$pH+pOH=14$

$pOH=14-11.87=2.13$

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

$[OH^-]=10^{-2.13}=0.00741 M$

The initial concentration of ethylamine = c = 0.100 M

$C_2H_5NH_2+H_2O\rightleftharpoons C_2H_5NH_3^{+}+OH^-$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_b=\frac{[C_2H_5NH_3^{+}][OH^-]}{[C_2H_5NH_2]}$ :

$K_b=\frac{x\times x}{(c-x)}$

$=\frac{0.00741\times 0.00741}{(0.100-0.00741)}$

$K_b=5.93\times 10^{-4}$

$5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

3 0

3 years ago

When pure methanol is mixed with water the resulting solution feels warm would you expect this solution to be ideal?Explain

Pepsi [2]

Answer:

No

Explanation:

In ideal solutions, the interactions between solute - solvent are approximately the same as those of solute - solute and solvent - solvent, that is the interactions are to be practically indistintiguishable after disolution.

The moment we have a release of energy (the solution feels warm) we are to conclude that there are strong interactions between the water and methanol molecules so we would expect the solution to be non ideal.

The reason for the interactions is the presence of hydrogen bonds between methanol and water.

5 0

3 years ago

Select the correct answer.

ser-zykov [4K]

Answer:

I think the answer would be option d.

hope it helps.

3 0

3 years ago

What is the pH of a solution in which [H 3O +] = 3.8 × 10 -8 M?

7nadin3 [17]

Answer:

<h3>The answer is 7.42 </h3>

Explanation:

The pH of a solution can be found by using the formula

$pH = - log [ { H_3O}^{+}]$

From the question we have

$pH = - log(3.8 \times {10}^{ - 8} ) \\ = 7.420216...$

We have the final answer as

<h3>7.42 </h3>

Hope this helps you

4 0

2 years ago