What is the definition of percent composition in your own words?

An unknown salt is either NaF, NaCl, or NaOCl. When 0.050 mol of the salt is dissolved in water to form 0.500 L of solution, the

victus00 [196]

Answer: The unknown salt is NaF

Explanation:

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

$\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Moles of salt = 0.050 moles

Volume of solution = 0.500 L

Putting values in above equation, we get:

$\text{Molarity of salt}=\frac{0.050mol}{0.500L}\\\\\text{Molarity of salt}=0.1M$

To calculate the hydroxide ion concentration, we first calculate pOH of the solution, which is:

pH + pOH = 14

We are given:

pH = 8.08

$pOH=14-8.08=5.92$

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

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

Putting values in above equation, we get:

$5.92=-\log[OH^-]$

$[OH^-]=10^{-5.92}=1.202\times 10^{-6}M$

The unknown salt given are formed by the combination of weak acid and strong acid which is NaOH

The chemical equation for the hydrolysis of $X^-$ ions follows:

$X^-(aq.)+H_2O(l)\rightleftharpoons HX(aq.)+OH^-(aq.);K_b$

Initial: 0.1

At eqllm: 0.1-x x x

Concentration of $OH^-=x=1.202\times 10^{-6}M$

The expression of $K_b$ for above equation follows:

$K_b=\frac{[OH^-][HX]}{[X^-]}$

Putting values in above expression, we get:

$K_b=\frac{(1.202\times 10^{-6})\times (1.202\times 10^{-6})}{(1-(1.202\times 10^{-6}))}\\\\K_b=1.445\times 10^{-11}M$

To calculate the acid dissociation constant for the given base 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

$K_b$ = Base dissociation constant = $1.445\times 10^{-11}$

Putting values in above equation, we get:

$10^{-14}=1.445\times 10^{-11}\times K_a\\\\K_a=\frac{10^{-14}}{1.445\times 10^{-11}}=6.92\times 10^{-4}$

We know that:

$K_a\text{ for HF}=6.8\times 10^{-6}$

$K_a\text{ for HCl}=1.3\times 10^{6}$

$K_a\text{ for HClO}=3.0\times 10^{-8}$

So, the calculated $K_a$ is approximately equal to the $K_a$ of HF

Hence, the unknown salt is NaF

6 0

3 years ago

Scientist looking for new substances in plants grind up the plants with methanol. This solvent dissolves many plant compounds. H

liubo4ka [24]

Answer:

See explanation

Explanation:

Crystals can be made from methanol by recrystallizing the plant extract from methanol.

The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.

The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.

4 0

3 years ago

What are you and what do you want with my attendance

Lelu [443]

Answer:

Such a waste of points but lol

8 0

3 years ago

Calculate the joules of heat needed to cool 159 g of water at 100 c to water at 65c

Butoxors [25]

Answer:

John is buying shirts for his softball team. He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered. Which equation can be used to find y, the total cost to buy xshirts? John is buying shirts for his softball team. He will pay a one-time processing fee of $27.50 and $12John is buying shirts for his softball team. He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered. Which equation can be used to find y, the total cost to buy xshirts? xdsz.75 per each shirt ordered. Which equation can be used to find y, the total cost to buy xshirts? John is buying shirts for his softball team. He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered. Which equation can be used to find y, the total cost to buy xshirts? John is buying shirts for his softball team. He will pay a one-time processing fee of $27.50 and $12.75 per each shirt ordered. Which equation can be used to find y, the total cost to buy xshirts?

Explanation:

4 0

3 years ago

Why should you clean up after every investigation

8_murik_8 [283]

You should clean up after every investigation because if you leave a mess, maybe another detective will come in and get lost because of the mess you left.

6 0

4 years ago

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