Please help me! Thank you

Answer:

0.967mole

Explanation:

Given parameters:

Volume of NH₄Cl  = 21.67L

Unknown:

Number of moles  = ?

Solution:

If we assume that the volume was taken at standard temperature and pressure,

 Then;

  Number of moles  = [tex]\frac{volume }{22.4L}[/tex]  

 Number of moles  = [tex]\frac{21.67}{22.4}[/tex]   = 0.967mole

Answer:Gained, Lost , Shared

Explanation:

The oxidation state tells you how many electrons an atom has GAINED.................. , LOST....................... , or SHARED........................ , in forming a compound.

Oxidation state is defined as the  the total number of electrons that an atom gains or loses when forming a chemical bond with another atom.

----To form an ionic bond for example in NaCl, Na, with 11 electrons and one valence electron in its outermost shell donates or lose that valence electron to Chlorine  with 17 electron and 7 in its outermost shell. Therefore Sodium, Na acquires the +1 oxidaton state to become stable and Chlorine acquires the -1 oxidation state  to become stable  forming the  NaCl compound.

To form a covalent compound, There must be sharing of electrons between atoms.For example, in PCl3,  The  phosphorous atom with atomic number 15 shares its three unpaired electrons with the single valence electrons of three chlorine atoms. making the four molecules to attain stability with  Phosphorous having +3 and the chlorine atoms having -1 oxidation states

a. double replacement

b. AB + CD ⇒ AD +CB

c and d

H₃PO₄ : Phosphoric acid

KOH : Potassium hydroxide

K₃PO₄ : Tripotassium phosphate

H₂O : water

Given

Reaction

H₃PO₄ + 3 KOH → K₃PO₄ + 3 H₂O

Required

Type of reaction

General equation

Name of reactants and product

Solution

Double replacement reaction : Cations and anions of different compounds switch places

It can also be said as a neutralization reaction because it produces water(reaction between an acid and a base)

AB + CD ⇒ AD +CB

H₃PO₄ : Phosphoric acid

KOH : Potassium hydroxide

K₃PO₄ : Tripotassium phosphate

H₂O : water

Answer:

4.99 ×10²³ molecules

Mass = 28.22 g

Explanation:

Given data:

Mass of H₂O₂ produced = ?

Mass of water react = 14.86 g

Number of molecules of H₂O₂ produced = ?

Solution:

Chemical equation:

2H₂O + O₂        →     2H₂O₂

Number of moles of water:

Number of moles = mass/molar mass

Number of moles = 14.86 g/ 18 g/mol

Number of moles = 0.83 mol

Now we will compare the moles of water and H₂O₂.

                   H₂O          :               H₂O₂

                    2              :                2

                  0.83           :             0.83

Mass of H₂O₂:

Mass = number of moles × molar mass

Mass = 0.83 mol × 34 g/mol

Mass = 28.22 g

Number of molecules:

1 mole = 6.022×10²³ molecules

0.83 mol × 6.022×10²³ molecules / 1 mol

4.99 ×10²³ molecules

Answer:

54.26 × 10²³ representative particles

Explanation:

Given data:

Number of moles of water = 9.01 mol

Number of representative particle = ?

Solution:

one mole of any substance contain 6.022 ×10²³ representative particles.

9.01 mol × 6.022 ×10²³ representative particles

54.26  ×10²³ representative particles

The number 6.022 × 10²³ is called Avogadro number.

"It is the number of atoms , ions , molecules or representative particles  in one gram atom of element, one gram molecules of compound and one gram ions of a substance "

Answer:

3.79 x 10²⁴atoms

Explanation:

Given parameters:

Number moles of lead  = 6.3moles

Unknown:

Number of atoms  = ?

Solution:

To solve this problem,

              1 mole of a substance contains  6.02 x 10²³ atoms

            6.3 mole of Pb  will contain 6.3  x 6.02 x 10²³ = 3.79 x 10²⁴atoms

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

Answer:

An ideal gas is a theoretical concept and a real gas behaves in an ideal manner under conditions which includes a high temperature and a low pressure such that the gas has high kinetic energy, and the intermolecular forces between the molecules are weak

The Ideal Gas Law is P·V = n·R·T

Where;

P = The pressure of the gas

V = The volume of the gas

n = The number of moles of the gas

R = The Universal Gas Constant

T = The temperature of the gas

For a gas cooled to 10 Kelvin and placed under high pressure, the interaction between individual gas molecules increases, and the kinetic energy of the gases is much lower and more comparable to the inter molecular forces between the gas molecules, which in turn produces observable changes from the initial ideal behavior of the gas such that the gas behavior deviates from the Ideal Gas Laws appreciably and are better modelled by the Van der Waals Equations which takes into account, the volume the gas particles occupy and the intermolecular forces between the molecules

The Van der Waals equation is presented as follows;

[tex]P = \dfrac{R \cdot T}{V - b} - \dfrac{a}{V^2}[/tex]

Where;

V = The molar volume

a = The gas constant a represents the attractive forces between the gas particles

b = Represent the volume occupied by the particles of the gas

Explanation:

Answer: A, B, & C

Explanation:

A. The ideal gas model assumes that gas particles experience no intermolecular attractions and these forces cause the gas to deviate from ideal behavior.

B. At very low temperatures, gas particles move slowly.

C. At very high pressures, gas particles are very close together.

Got it right on edge :)

Answer:

C. Hydrogen Ions.

Explanation:

The pH level of soils is measured based upon the acidity or basicity level in the soil. The pH scale usually measures between 0-14. 7 is the neutral pH level of soil and a pH level below 7 is considered acidic and above 7 is alkaline.

So, soil with a high amount of hydrogen ions (H+) will be considered acidic. As the amount of hydrogen ions increases in the soil, the pH level of the soil decreases, making it acidic.

Therefore, option C is correct.

Answer:

Scientific Method.

Explanation:

A scientific method is basically a method or a process when you conduct an experiment. Normally, the process goes like this:

1. You make like a question or something that you want to investigate, it's like the aim of the experiment.

2. You make an experiment and a hypothesis. A hypothesis is basically a guess on how the results of the experiment would turn out. You don't have to be correct for the hypothesis since there is no right or wrong answer.

3. Conduct the experiment. I don't think this needs a detailed explanation since experiments vary from one another.

4. Collect results. The data you collect come in different ways based on your experiment, but it is crucial you get data so that you can answer your question in 1.

5. Make inferences. You can't directly get a conclusion or answer from the results, so inferences are needed.

6. Craft a conclusion or answer. This is the final step when conducting an experiment and the part where you have the answer you needed when you conducted the experiment :)

Answer:

15 m/min

Explanation:

You take the 1500 divide by 10 and your answer is 15

Answer:

4 weeks

Explanation:

It takes 4 weeks for the cyclle to be happening again

Answer:

A

Explanation:

A Equations showing which elements are oxidized and which are

Answer:

A.

Explanation:

Equations showing which elements are oxidized and which are

reduced

Explanation:

this question tion is so hard sorry but I can't do is sorry

0.50 mol SiO₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

30 g SiO₂ (sand)

Step 2: Identify Conversions

Molar Mass of Si - 28.09 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of SiO₂ - 28.09 + 2(16.00) = 60.09 g/mol

Step 3: Convert

Step 4: Check

Follow sig figs and round. We are given 2 sig figs.

0.499251 mol SiO₂ ≈ 0.50 mol SiO₂

Answer:

[tex]\boxed {\boxed {\sf About \ 0.5 \ moles \ of \ SiO_2}}[/tex]

Explanation:

To convert from grams to moles, we must use the molar mass.

1. Molar Mass

Use the Periodic Table to find the masses of the individual elements (silicon and oxygen) in sand.

Examine the formula for sand: SiO₂. There is a subscript of 2 after oxygen, so there must be 2 oxygen atoms. Multiply oxygen's mass by 2 and add silicon's mass to find the molar mass of sand.

2. Calculate Moles

Use the molar mass as ratio.

[tex]\frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Multiply by the given number of grams (30)

[tex]30 \ g \ SiO_2 * \frac{60.083 \ g \ SiO_2}{1 \ mol \ SiO_2}[/tex]

Flip the fraction so the grams of sand will cancel.

[tex]30 \ g \ SiO_2 *\frac{1 \ mol \ SiO_2}{60.083 \ g \ SiO_2}[/tex]

[tex]30 *\frac{1 \ mol \ SiO_2}{60.083 }[/tex]

[tex]\frac{30 \ mol \ SiO_2}{60.083 }[/tex]

[tex]0.499309289 \ mol \ SiO_2[/tex]

3. Round

The original measurement of grams has 1 signfiicant figure. We must round our answer to 1 sig fig.

For the answer we found, that is the tenth place. The 9 in the hundredth tells us to round the 4 to a 5.

[tex]\approx 0.5 \ mol \ SiO_2[/tex]

There are about 0.5 moles of SiO₂ in 30 grams.

Answer:

1: C

2: A

3: B

4: I

5: G

6: H

Explanation:

Please don't crucify me if I'm wrong ;-;

Answer:

VALENCE ELECTRONS are involved in the bonding of atoms

Explanation:

Hope that helps

First, it combines with carbon dioxide in the soil to form a weak acid called carbonic acid. ... Carbonic acid slowly dissolves away minerals in rock, especially the carbonate minerals that make up limestone and marble. The weak acid decomposes the insoluble rock into watersoluble products that move into the groundwater.

Answer:

C.  physical

Explanation:

A mixture is a physical combination. Mixtures are combinations of compounds and molecules without any chemical reaction taking place.

Mixtures have the following properties:

Answer:

a region around a magnetic material or a moving electric charge within which the force of magnetism acts. hope it helps :)

Answer:

is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials

Explanation:

Answer:

12.736 grams of hydrogen peroxide

Explanation:

Explanation:

Given parameters:

Mass of carbon dioxide  = 250g

Molar mass of carbon dioxide  = 44.01g/mol

Unknown:

Number of moles of carbon dioxide  = ?

Number of molecules of carbon dioxide  = ?

Solution:

We first find the number of moles of carbon dioxide;

 Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

  Number of moles  = [tex]\frac{250}{44.01}[/tex]   = 5.68moles

 From mole concept;

          1  mole of a substance contains 6.02 x 10²³ molecules

      5.68 mole of carbon dioxide will contain 5.68 x  6.02 x 10²³

                                                                = 3.42 x 10²⁴molecules

Answer:

Lithium sulphate (Li₂SO₄) and water (H₂O

Explanation:

H₂SO₄ + 2LiOH —> Li₂SO₄ + 2H₂O

The equation represented above indicates a neutralization reaction.

A neutralization reaction is a reaction involving acid and base which result in the production of salt and water.

In the equation above,

Reactant:

H₂SO₄ (acid)

LiOH (base)

Product:

Li₂SO₄ (salt)

H₂O (water)

Thus, lithium sulphate (Li₂SO₄) and water (H₂O) are the products of the reaction

Answer:

B its most likely sorry if im wrong :D :(

Explanation:

Answer:

D . A substance with a pH of 8

Explanation:

pH stands for "Potential for Hydrogen." This is an indicator of a solution's acidity or alkalinity. It is also used to tell which chemicals are great for cleaning.

pH 7 and pH 8 are both considered "neutral pH," thus, solutions with these pH are often used as dishwashing detergents because they do not destroy the surfaces of objects. However, pH 8 is said to be more alkaline in nature. This allows it to destroy the residues, such as fats and oils, in pots and pans. It is the pH of baking soda.

Answer:

The pair of arrows which represents the relationship of speeds of the two cars is;

The second option as shown in the attached drawing

Explanation:

The given parameters are;

The reading on the speedometer of one car = 20 m/s

The reading on the speedometer of the other car = 72 km/h = 20 m/s

The blue arrow = 20 m/s

Therefore, given that the speeds of both cars are equal (20 m/s = 72 km/h = 20 m/s),  the pair of arrows that represent the relationship of speeds of the two cars is two equal length blue arrows which is the second option

The attached diagram showing the pair of arrows that represents the relationship of speeds of the two cars is drawn using Microsoft Visio.