which statement is true about alkali metals?

A. Some of them explode when exposed to water.
B. They aren't conductors of heat or electricity.
C. They're in group 18 of the periodic table.
D. They aren't very reactive​

Taking into account the definition of molarity,  the molarity of a solution that contains 30 moles naoh in 0.80 liters of solution is 37.5 \(\frac{moles}{liters}\).

Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:

\(Molarity=\frac{number of moles}{volume}\)

Molarity is expressed in units \(\frac{moles}{liters}\).

In this case, you have:

Replacing in the definition of molarity:

\(Molarity=\frac{30 moles }{0.80 L}\)

Solving:

Molarity= 37.5 \(\frac{moles}{liters}\)

Finally, the molarity of a solution that contains 30 moles naoh in 0.80 liters of solution is 37.5 \(\frac{moles}{liters}\).

Learn more about molarity:

brainly.com/question/9324116

brainly.com/question/10608366

brainly.com/question/7429224

#SPJ1

Answer:

6

What do AIA, SAG, AFP and AMA all stand for? Select four options.

American Institute of Architects

American Society of Mechanical Engineers

American Medical Association

Screen Actors Guild

Association for Finance Professionals

Professional Colleges

Answer:

3.39 mol

Explanation:

n = m/M, where n is moles, m is mass and M is molar mass.

n = 149/44.01

n = 3.38559418314 mol

n = 3.39 mol

Hope that helps

Answer:

The troposphere is the lowest layer of Earth's atmosphere, and is also where nearly all weather conditions take place. It contains 75% of the atmosphere's mass and 99% of the total mass of water.

Explanation:

Answer:

For a mild human cough in air at 20 °C and 50% relative humidity, we found that ... larger droplets are dispersed into smaller ones gradually while moving away from the ... Complex phase change and transport phenomena such as evaporation and ... Natural Ventilation for Infection Control in Health-Care Settings

Explanation

Answer:

The following are six of the most powerful hurricanes to make landfall on the mainland United States based on minimum pressure: - Florida Keys Labor Day hurricane, 1935, 892 mb The hurricane struck the Florida Keys as a Category 5, the highest ranking possible on the five-step Saffir-Simpson scale.

Explanation:

Answer:

Explanation:

yes

Answer:

I multiply 97.21 by the amount of cookies you have.

Explanation:

i dont know if this is correct but i multiplyed it by two and got 194.42

Since Potassium atom is made up of 19 electrons, that is, its atomic number is 19; therefore the electronic configuration that represents potassium in an excited state is 1s²2s²2p⁶3s²2p⁶4s⁰4p¹

The electron configuration that represents an excited state for a potassium atom is 2-8-7-1. Option (1) is correct.

Potassium is a chemical element with the symbol K (from Neo-Latin kalium) and atomic number 19. The electron configuration of potassium is 1s²2s²2p⁶3s²3p⁶4s¹.

The excited state of potassium would be when one of the 4s electrons jumps to a higher energy level (orbital) such as 4p, 5s, 5p, etc. resulting in an electron configuration of 2-8-7-1.

So, the option (1) 2-8-7-1 represents the excited state for a potassium atom.

The distribution of electrons in an element's atomic orbitals is described by its electron configuration. Atomic electron configurations follow a standard notation in which all electron-containing atomic subshells are arranged in a particular order, with the number of electrons they hold written in superscript.

Know more about electron configuration:

https://brainly.com/question/29157546

#SPJ2

Answer:

calcium chloride because that is the answer

When choosing a substance for use in a cooling system, we want a substance that can absorb a large amount of heat without undergoing a significant temperature change. This is where the specific heat capacity of a substance comes into play.

The specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of one unit of mass of the substance by one degree Celsius (or Kelvin). A substance with a high specific heat capacity requires more heat to raise its temperature by a certain amount than a substance with a low specific heat capacity. Therefore, a substance with a high specific heat capacity would be best for use in a cooling system.

Out of the options given, a liquid with a high specific heat would be the best choice for use in a cooling system. Liquids have a higher specific heat than gases, which makes them better at absorbing and storing heat. Additionally, liquids have a higher thermal conductivity than solids, which means they can more efficiently transfer heat from one location to another.

Moreover, among the liquids, water is a commonly used coolant due to its high specific heat capacity, which means it can absorb a large amount of heat without undergoing a significant temperature change. Additionally, water has a high boiling point, which makes it effective at absorbing heat from high-temperature sources without boiling and evaporating.

In summary, a liquid with a high specific heat, such as water, would be the best choice for use in a cooling system due to its ability to absorb and store heat efficiently.

For more such question on heat capacity visit:

https://brainly.com/question/16559442

#SPJ11

Answer:

B. Hydrogen and oxygen molecules

General Formulas and Concepts:

Chemistry - Reactions

Explanation:

Step 1: Define

Reaction RxN:   2H₂ + O₂ → 2H₂O

Step 2: Identify

Reactants:   H₂ and O₂

Products: H₂O

Answer:

The balanced chemical equation is:

- Ratio of Al2O3 to O2: 2:3R

- Ratio of Al2O3 to Al: 2:4R

- Ratio of Al to O2: 4:3R

Explanation:

To balance the chemical equation, it is necessary to have the same amount of elements on the reactant side as on the product side:

Now we know that the reaction is balanced, because on the reactant side and on the products side there are:

- 4 Al

- 6 O

Now that the equation is balanced, we can write the ratios with the stoichiometry of the reaction.

The standard enthalpy change for reaction (3) is 117.1 kJ.

The standard enthalpy change for reaction (3) can be calculated by using the enthalpy changes of reactions (1) and (2) and applying Hess's Law.

To do this, we need to manipulate the given equations so that the desired reaction (3) can be obtained.

First, we reverse reaction (1) to get the formation of C2H4(g) from C2H6(g):

C2H4(g)C2H6(g) ΔH° = -52.3 kJ

Next, we multiply reaction (2) by 2 and reverse it to obtain 2 moles of C2H6(g) reacting to form 3 moles of H2(g):

2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ

Now, we add the two modified equations together:

C2H4(g)C2H6(g) ΔH° = -52.3 kJ
2C2H6(g)2C(s) + 3H2(g) ΔH° = 169.4 kJ

When adding these equations, the C2H6(g) on the left side cancels out with the C2H6(g) on the right side, leaving us with the desired reaction (3):

C2H4(g) + H2(g)C2H6(g) ΔH° = -52.3 kJ + 169.4 kJ = 117.1 kJ

Learn more about standard enthalpy here :-

https://brainly.com/question/28303513

#SPJ11

0.18 L of solution can be prepared using 7.55g of KCl if the final molarity is 0.55M.

Molarity (M) is known to be the amount of a substance in a given volume of solution which is usually is defined as the number of moles of solute per liter of solution.

Both molarity and molarity are measures of the concentration of a chemical solution. The main difference between the two is mass and volume. Molarity refers to the moles of solute to the mass of the solvent, and molarity refers to the moles of solute to the volume of the solution.

Let's calculate no. of moles first:

No. of moles = Mass/Molecular mass

Mass of given KCl = 7.55 g

Molecular mass of KCl = 74.5513 g/mol

No. of moles = 7.55/74.5513

No. of moles = 0.100 mol

Now, for the calculation of molarity:

Molarity = No. of moles/V of solution

0.55 = 0.100/V

V = 0.100/0.55

V = 0.18 L

To know more about molarity, visit:

https://brainly.com/question/8732513

#SPJ1

Answer:

answer is 125

Explanation:

180-55= 125

Answer:

7.28 moles Ag°

Explanation:

              Cu°          +    2 AgNO₃  => Cu(NO₃)₂ + 2Ag°

Given 7.28 moles     7.28 moles

To determine limiting reactant, divide the mole values by the respective coefficient of balanced equation. The resulting smallest value is the limiting reactant. Note: this is a short cut method for determining limiting reactant only. Once the limiting reactant is determined one must use the given mole values of the limiting reactant to solve problem. That is ...

Limiting reactant determination:

              Cu°          +    2 AgNO₃  => Cu(NO₃)₂ + 2Ag°

Cu: 7.28 / 1  = 7.28

AgNO₃ : 7.28 / 2 = 3.64 => Limiting Reactant is AgNO₃

Solving Problem depends on AgNO₃; Cu will be in excess.

Since coefficients of AgNO₃ & Ag° are equal, then the moles AgNO₃ used equals moles Ag° produced and is therefore 7.28 moles Ag°.

Answer:

Neptune and Saturn although Neptune isn't on there so just Saturn.

hope it'll help ya out!

the standard enthalpy change of formation for MgO(s) is -393.5 kJ/mol

"What is the standard change in enthalpy of formation of MgO(s)?",

the answer would be -601.8 kJ/mol.

This is the standard enthalpy change of formation for magnesium oxide, which is a measure of the energy required to form one mole of the substance from its constituent elements under standard conditions.

The equation for the formation of MgO(s) is:Mg(s) + 1/2 O2(g) → MgO(s)

The standard enthalpy change of formation can be calculated using the following equation:

ΔHf°(MgO) = ΣΔHf°(products) - ΣΔHf°(reactants)

In this equation, ΔHf°(MgO) represents the standard enthalpy change of formation for magnesium oxide, ΣΔHf°(products) represents the sum of the standard enthalpy changes of formation for the products (in this case, only MgO),

and ΣΔHf° (reactants) represents the sum of the standard enthalpy changes of formation for the reactants (in this case, Mg and O2).

Using standard enthalpies of formation values given in tables, we can calculate that:

ΔHf°(MgO) = [0 kJ/mol + (-393.5 kJ/mol)] - [0 kJ/mol + 0 kJ/mol]

ΔHf°(MgO) = -393.5 kJ/mol

Therefore, the standard enthalpy change of formation for MgO(s) is -393.5 kJ/mol.

To know more about standard enthalpy here

https://brainly.com/question/29556033

#SPJ11

Answer:

64.17 Moles of Au

Explanation:

(atoms and particles are the same)

3.85 x 10 ^25 x (1 mol              

                         /6.02 x 10^23)

3.85 / 6 = .64166

.6416 x 10^2 = 64.166

If you round up the answer you will get 64.17

64.17  moles of Au

Answer:

The answer is 5.73 moles Au

In picture one, there are four electrons, one valance electrons and two shells, in image two there are three electrons, one valance electrons and two shells whereas there are 13 electrons, three valance electrons and three shells.

Electrons:

An electron is a negatively charged particle which can be either bounded with to an atom. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure.

Valence Electrons:

Valence electrons are those electrons which are present in outermost shell or in valence shell or energy level of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell.

Electron Shells Numbers:

Each shell can contain only a fixed number of electrons: the first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on.

So we can conclude that In picture one, there are four electrons, one valance electrons and two shells, in image two there are three electrons, one valance electrons and two shells whereas there are 13 electrons, three valance electrons and three shells.

Learn more about Valence Electrons here: brainly.com/question/371590

#SPJ1

A 20.0 g sample of calcium contains approximately 3.01 x 10^23 calcium atoms.

To determine the number of calcium atoms in a 20.0 g sample of calcium (Ca), we need to use the concept of Avogadro's number and molar mass.

The molar mass of calcium (Ca) is approximately 40.08 g/mol. This value represents the mass of one mole of calcium atoms.

To calculate the number of calcium atoms in the given sample, we can use the following steps:

   Determine the number of moles of calcium in the sample:

   Number of moles = Mass / Molar mass

   Number of moles = 20.0 g / 40.08 g/mol

   Use Avogadro's number to convert moles to atoms:

   Number of atoms = Number of moles * Avogadro's number

   Number of atoms = Number of moles * 6.022 x 10^23 atoms/mol

Substituting the calculated number of moles into the equation:

Number of atoms = (20.0 g / 40.08 g/mol) * (6.022 x 10^23 atoms/mol)

Performing the calculation:

Number of atoms ≈ 3.01 x 10^23 atoms

Therefore, a 20.0 g sample of calcium contains approximately 3.01 x 10^23 calcium atoms.

learn more about "calcium ":- https://brainly.com/question/26636816

#SPJ11

A photomultiplier tube works by detecting incoming light, converting it into electrons through the photoelectric effect, amplifying the signal through a series of dynodes, and generating an electrical output that can be measured or analyzed.

1. Incoming light: The PMT detects incoming light, usually in the form of photons, through its entrance window.

2. Photoelectric effect: When the photons hit the photocathode (a light-sensitive surface) inside the PMT, they release electrons through the photoelectric effect. This is the process where electrons are emitted from a material when it absorbs energy from light.

3. Electron multiplication: The released electrons are then accelerated towards a series of electrodes called dynodes. Each dynode has a positive voltage relative to the previous one, causing the electrons to gain energy and multiply via secondary emission as they move through the PMT.

4. Signal amplification: As the electrons pass through the series of dynodes, the number of electrons increases exponentially, resulting in a significant amplification of the initial signal.

5. Signal detection: The multiplied electrons eventually reach the anode, which collects them and generates an electrical current proportional to the intensity of the incoming light.

6. Output: The electrical current generated at the anode is then passed through an external circuit, where it can be further amplified, measured, or analyzed.
To know more about Photomultiplier Tube:

https://brainly.com/question/28439635

#SPJ111

Answer:

PubChem CID 6393

Structure  

Find Similar Structures

Chemical Safety  

Compressed Gas

Laboratory Chemical Safety Summary (LCSS) Datasheet

Molecular Formula CF4

Molecular Weight  

88.004 g/mol

Explanation:

The mass percent of the unknown solute in the solution will be approximately 3.92%.

Mass percent, also known as weight percent or mass/mass percent, is a unit of concentration that expresses the mass of a solute in a solution as a percentage of the total mass of the solution.

To calculate the mass percent of the unknown solute in the solution, we need to divide the mass of the solute by the mass of the entire solution and then multiply by 100.

Mass of solute = 32.43 grams (given)

Mass of solution = 826.51 grams (given)

Mass percent = (Mass of solute / Mass of solution) × 100

Substituting the given values;

Mass percent = (32.43 g / 826.51 g) × 100

≈ 3.92%

Therefore, the mass percent is approximately 3.92%.

To know more about mass percent here

https://brainly.com/question/5840377

#SPJ4

Ethanol is produced when ethane and ethene react with water and a catalyst like sulfuric acid. Adding concentrated sulfuric acid to hot ethanol (acts as a catalyst).

To eliminate carbon dioxide and sulphur dioxide that are created as byproducts, the gases are passed through a sodium hydroxide solution. The main product that is gathered over water is ethene. As a result, dehydration of ethanol produces ethene rather than ethane. The names Mattling acid and Oil of Vitriol are other names for sulfuric acid. It is highly caustic and acidic in nature. It dehydrates and oxidises when  present in higher amounts. It is a clear, syrup-like liquid with no colour or smell. A substance having the chemical formula C 2H 6, ethane is an organic chemical.

Learn more about ethanol here

https://brainly.com/question/25002448

#SPJ4

Provide a few solutions and explain why they should be effective. Make a succinct conclusion. Provide a succinct summary of what you wrote. A good response.

What might a solution look like?

A good example of a solution is a mixture of salt and sugar. Any solution can be broken down into different parts. Solid, liquid, and gaseous solutions can be classified as solutions based on the physical states of the solvent and solute. Both the solute and the solvent have a solid in solid solutions. For instance, mixtures of polymer and ceramic.

What various categories of water-based solutions are there?

1. Depending on whether the solution contains water or not, different kinds of solutions on water as a solvent can be divided into two categories. the mixture in which freshwater acts as just a solvent and any state of homogenous component totally dissolves in it.

To know more about solutions visit:

https://brainly.com/question/30665317

#SPJ1

Answer:

yes I do

But I can't see the question very well

Explanation:

Answer:

no it's is false because an electron have negative charges and it is not inside the atom and it is found out side the nucleus

We expect the release of PCO2 from the bottle, When the cork is pulled.

When the cork is pulled, we expect the release of PCO2 in the atmosphere to happen because there is high concentration of PCO2 in the bottle but there is no concentration of PCO2 in the atmosphere so due to diffusion, the PCO2 gas moves outside the bottle.

So we can conclude that When the cork is pulled, the release of PCO2 from the bottle will be expected.

Learn more about pressure here: https://brainly.com/question/25736513

#SPJ1