What is the combustibility of matter?

The statement "Although sulfuric acid is a strong electrolyte, an aqueous solution of H2SO4 contains more HSO4− ions than SO42−

PIT_PIT [208]

The statement "Although sulfuric acid is a strong electrolyte, an aqueous solution of H₂SO₄ contains more HSO₄⁻ ions than SO₄²⁻ ions is True. This is best explained by the fact that H₂SO₄ is a diprotic acid where only the first hydrogen completely ionizes.

Why?

H₂SO₄ is a diprotic acid. That means that it has two hydrogen ions to give to the solution. The two dissociation reactions are shown below:

H₂SO₄ + H₂O → HSO₄⁻ + H₃O⁺

HSO₄⁻ + H₂O ⇄ SO₄²⁻ + H₃O⁺

As the arrows show, the first dissociation is complete, meaning that all the sulfuric acid that is present initially is dissociated into HSO₄⁻ and H₃O⁺. However, the second dissociation is incomplete, and it's actually an equilibrium with an acid constant (Ka)of 1.2×10⁻².

That means that if the initial concentration of H₂SO₄ was 1M, the concentration of HSO₄⁻ is going to be 1M as well, but the concentration of SO₄²⁻ is going to be much less than 1M, according to the dissociation constant.

Have a nice day!

4 0

3 years ago

A compound is 7.74% hydrogen and 92.26% carbon by mass. At 100°C a 0.6883 g sample of the gas occupies 250 mL when the pressure

ycow [4]

Answer: The molecular formula for the compound is $C_6H_6$

Explanation:

We are given:

Percentage of C = 92.26 %

Percentage of H = 7.74 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of C = 92.26 g

Mass of H = 7.74 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Carbon = $\frac{\text{Given mass of Carbon}}{\text{Molar mass of Carbon}}=\frac{92.26g}{12g/mole}=7.68moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{7.74g}{1g/mole}=7.74moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 7.68 moles.

For Carbon = $\frac{7.68}{7.68}=1$

For Hydrogen = $\frac{7.74}{7.68}=1$

Step 3: Taking the mole ratio as their subscripts.

The ratio of C : H = 1 : 1

The empirical formula for the given compound is $CH$

Calculating the molar mass of the compound:

To calculate the molecular mass, we use the equation given by ideal gas equation:

PV = nRT

Or,

$PV=\frac{m}{M}RT$

where,

P = pressure of the gas = 820 torr

V = Volume of gas = 250 mL = 0.250 L (Conversion factor: 1 L = 1000 mL )

m = mass of gas = 0.6883 g

M = Molar mass of gas = ?

R = Gas constant = $62.3637\text{ L. torr }mol^{-1}K^{-1}$

T = temperature of the gas = $100^oC=(100+273)K=373K$

Putting values in above equation, we get:

$820torr\times 0.250L=\frac{0.6883g}{M}\times 62.3637\text{ L torr }mol^{-1}K^{-1}\times 373K\\\\M=\frac{0.6883\times 62.3637\times 373}{820\times 0.250}=78.10g/mol$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is:

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 78.10 g/mol

Mass of empirical formula = 13 g/mol

Putting values in above equation, we get:

$n=\frac{78.10g/mol}{13g/mol}=6$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$C_{(1\times 6)}H_{(1\times 6)}=C_6H_6$

Hence, the molecular formula for the compound is $C_6H_6$

8 0

3 years ago

Burning wood in a fireplace is an example of what kind of energy conversion?

S_A_V [24]

Answer:

A. because the wood is stored chemical energy and it is converting into heat energy

8 0

3 years ago

Read 2 more answers

Draw and label the structure of a sodium atom showing the distribution of electrons

Korolek [52]

Answer:

Please, find the drawing in the picture attached.

Explanation:

A simple model or drawing of the structure of an atom may be performed showing the electrons on the different energy levels (shells), plus the nucleons (protons and neutrons).

Then, you need the information on:

number of protons (atomic number)
electron configuration
number of neutrons

The first step is to find the atomic number of the atom. You find that information in the periodic table, where the elements are show with their chemical symbol.

The chemical symbol of sodium is Na. It is located in the group (colum) 1 and period (raw) 3. There you find that the atomic number is 11. Hence your drawing must show 11 protons.

Since the atom is neutral, the number of electrons is also 11. So, you must place the electrons in the following energy levels or shells:

Main energy level shell number of electrons

n = 1 K 2 (this is the maximum in this level)

n= 2 L 8 (this is the maximun in this level)

n= 3 M 1 (the maximum in this level is 18)

Now that you have the number of protons and the location of the electrons, you must determine the number of neutrons.

In the periodict table you will also find the atomic mass of the elements. The atomic mass of sodium is 22.990 amu. That means that most sodium atoms have mass number (number of protons plus neutrons) 23. Some isotopes will have less neutrons, but you can draw your model using the most typical isotope with 23 nucleons. This means, that the number of neutrons is 23 nucleons - 11 protons = 12 neutrons.

8 0

3 years ago

How many formula units are found in 2.10 gram of Mgo? (No units needed.)

disa [49]

Answer:

84.63924

Explanation:

one moles equals 40.30440

8 0

2 years ago