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3 years ago

Hey! I was wondering how to get the solution to this question!

Chemistry

1 answer:

zzz [600]3 years ago

3 0

Answer:

6.22 × 10⁻⁵

Explanation:

Step 1: Write the dissociation reaction

HC₆H₅COO ⇄ C₆H₅COO⁻ + H⁺

Step 2: Calculate the concentration of H⁺

The pH of the solution is 2.78.

pH = -log [H⁺]

[H⁺] = antilog -pH = antilog -2.78 = 1.66 × 10⁻³ M

Step 3: Calculate the molar concentration of the benzoic acid

We will use the following expression.

Ca = mass HC₆H₅COO/molar mass HC₆H₅COO × liters of solution

Ca = 0.541 g/(122.12 g/mol) × 0.100 L = 0.0443 M

Step 4: Calculate the acid dissociation constant (Ka) for benzoic acid

We will use the following expression.

Ka = [H⁺]²/Ca

Ka = (1.66 × 10⁻³)²/0.0443 = 6.22 × 10⁻⁵

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Pls help this is due in 10 minutes can someone tell me question 4

Veronika [31]

Answer:

Then the person will only have the dominant trait. There needs to be two recessive genes in order for that gene to appear.

Explanation:

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3 years ago

Please help asappp‍♀️!

solniwko [45]

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3 years ago

Read 2 more answers

How many grams of zinc metal will react completely with 7.8 liters of 1.6 M HCl? Show all of the work needed to solve this probl

Andru [333]

Answer:

For 1: The correct answer is 407.97 grams.

For 2: The correct answer is 76.72 grams.

Explanation:

For 1:

We are given the molarity of HCl, to find the moles of HCl, we use the formula:

$Molarity=\frac{\text{Moles}{\text{Volume}}$

We are given:

Molarity = 1.6 M

Volume = 7.8 L

Putting values in above equation, we get:

$1.6mol/L=\frac{\text{Moles of HCl}}{7.8L}\\\\\text{Moles of HCl}=12.48mol$

For the given reaction:

$Zn(s)+2HCl(aq.)\rightarrow ZnCl_2(aq.)+H_2(g)$

By Stoichiometry of the reaction:

2 moles of HCl reacts with 1 mole of zinc metal.

So, 12.48 moles of HCl react with = $\frac{1}{2}\times 12.48=6.24mol$ of Zinc metal.

To calculate the mass of zinc metal, we use the formula:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Molar mass of Zinc metal = 65.38 g/mol

$6.24=\frac{\text{Mass of zinc metal}}{65.38g/mol}\\\\\text{Mass of zinc metal}=407.97g$

For 2:

We are given that 298 grams of 83.1 % by mass of iron (II) nitrate solution are present.

So, mass of Iron (II) nitrate solution will be = $\frac{83.1}{100}\times 298=247.638g$

Molar mass Iron (II) nitrate = 180 g/mol

Putting values in equation 1, we get:

$\text{Moles of }Fe(NO_3)_2=\frac{247.638g}{180g/mol}=1.37mol$

For the following reaction:

$2Al(s)+3Fe(NO_3)_2(aq.)\rightarrow 3Fe(s)+2Al(NO_3)_3(aq.)$

By Stoichiometry of the reaction:

3 moles of $Fe(NO_3)_2$ produces 3 moles of iron metal.

So, 1.37 moles of $Fe(NO_3)_2$ will produce = $\frac{3}{3}\times 1.37=1.37mol$ of iron metal.

To calculate the mass of zinc metal, we equation 1:

$1.37=\frac{\text{Mass of iron metal}}{56g/mol}\\\\\text{Mass of iron metal}=76.72g$

5 0

3 years ago

Which equation correctly converts degrees Celsius to kelvins?

lina2011 [118]

Answer:

Explanation:

To convert from celcius to kelvin add 273 to the celcius number. D has -75 celcius so if you add -75 to 273 you get 198 K

5 0

3 years ago

Cyanogen is a gas which contains 46.2% C and 53.8% N by mass. At a temperature of 25°C and a pressure of 750 mm Hg, 1.50 g of cy

sergiy2304 [10]

Answer:

Molecular formula of cyanogen is C₂N₂

Explanation:

We apply the ideal gases law to find out the mole of cyanogen

P . V = n. R. T

Firstly let's convert the pressure in atm, for R

750 mmHg = 0.986 atm

25°C + 273 = 298K

0.986 atm . 0.714L = n . 0.082 L.atm/mol.K .298K

(0.986 atm . 0.714L) / (0.082 L.atm/mol.K .298K) = n

0.0288 mol = n

Molar mass of cyanogen = mass / mol

1.50 g /0.0288 mol = 52.02 g/m

Let's apply the percent, to know the quantity of atoms

100 g of compound contain 46.2 g of C and 53.8 g of N

52.02 g of compound contain:

(52.02 . 46.2) / 100 = 24 g → 2 atoms of C

(52.02 . 53.8) / 100 = .28 g → 2 atoms of N

3 0

3 years ago