What type of wave is a s-wave and how does energy move through the wave

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

2 years ago

A sample of helium gas has a volume of 620. Ml at a temp of 500 K. If we decrease the temperature to 100K while keeping the pres

Ne4ueva [31]

Answer:

A sample of helium gas has a volume of 620mL at a temperature of 500 K. If we ... to 100 K while keeping the pressure constant, what will the new volume be?

Explanation:

3 0

2 years ago

However, when the temperature increases, the solubility of gaseous solutes will _______?

babunello [35]

Answer:

Decrease

Explanation:

Since the speed in which the gas molecules are faster as they are heated, they fly around in the container and logically, it is harder to insert a moving object into water than something more stationary or slower.

7 0

2 years ago

In subsequent experiments you determine that the compound is iron (II) chloride. Which of the following properties would you als

Naddika [18.5K]

Answer:

b. Conducts electricity when dissolved in water

Explanation:

Iron(II) chloride, is the chemical compound with formula FeCl2.

It is a solid with a high melting point of about 677 degree Celsius or 950 K when in anhydrous form but have lower melting point in hydrated form.

The compound is often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in the laboratory.

There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.

7 0

2 years ago

You are the medical examiner at the scene of a murder at a restaurant. There is a

Hoochie [10]

The compound : C₄₀H₄₄N₄O

<h3>Further explanation</h3>

The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components

The principle of determining empirical formula

• Determine the mass ratio of the constituent elements of the compound.

• Determine the mole ratio by dividing the percentage by the atomic mass

The mol ratio of composition : C : H : N : O

$\tt \dfrac{80.66}{12}\div \dfrac{7.39}{1}\div \dfrac{9.39}{14}\div \dfrac{2.68}{16}\\\\6.722\div 7.39\div 0.671\div 0.1675\rightarrow divide~by~smallest(0.1675)\\\\40\div 44\div 4\div 1$

3 0

2 years ago