Using distributive property solve 9×19​

Answer:

Expiremental group for -first one.    Second one-2

Explanation:

I Had Those QuestIons On mY tEsttt!!

Answer:

S<Se<Te

Br<Ni<K

F<Si<Ba

Explanation:

Step 1

The reaction is written and balanced:

4 Rb + O2 =>2 Rb2O

-----------

Step 2

Define % yield of product (Rb2O) = (Actual yield/Theoretical yield) x 100

The actual yield is provided by the exercise = 39.7 g

----------

Step 3

Determine the limiting reactant. The molar masses are needed to solve this:

For Rb) 85.4 g/mol

For O2) 32 g/mol

Procedure:

4 Rb + O2 =>2 Rb2O

4 x 85.4 g Rb ----- 32 g O2

82.4 g Rb ----- X = 7.72 g O2 are needed

For 82.4 g Rb, 7.72 g O2 is needed, but there is 11.6 g O2. Therefore, O2 is the excess agent. Rb is the limiting reactant.

--------

Step 4

Determine the theoretical yield from the limiting reactant:

The molar mass Rb2O) 187 g/mol

Procedure:

4 x 85.4 g Rb ------ 2 x 187 g Rb2O

82.4 g Rb ------ X = 90.2 g Rb2O = Theoretical yield

---------

Step 5

% yield = Actual y./Theoretical y. x 100 = (39.7 g/90.2 g) x 100 = 44 % approx.

Answer: % yield = 44 %

In double replacement reactions, two metals not combine with each other when products are formed because, metals form negative ions and like charges attract. Therefore, option A is correct.

A metal is a substance that exhibits a shiny appearance when freshly processed, polished, or shattered, and conducts electricity and heat rather well. Generally speaking, metals are malleable and ductile.

We use the (s) symbol for solid because salt is an insoluble substance that will not dissolve in water. The silver, fluoride, potassium, and chloride ions would have effectively moved to a new location if there had been no precipitate formation, but they would still be floating around as ions. In this instance, nothing happens.

When two ionic compounds exchange ions and create two new ionic compounds, this is known as a double replacement reaction.

Thus, option A is correct.

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Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

\(P_1V_1 = P_2V_2\)

Since we're finding the new volume

\(V_2 = \frac{P_1V_1}{P_2} \\\)

We have

\(V_2 = \frac{100 \times 740}{780} = \frac{74000}{780} \\ = 94.8717...\)

We have the final answer as

Hope this helps you

Answer:

A common effect of UV radiation is erythema or sunburn.

Explanation:

This happens when skin cells are damaged by the absorption of energy from UV rays.

Answer:

A common effect of UV radiation is erythema or sunburn.

Explanation:

This happens when skin cells are damaged by the absorption of energy from UV rays.

Answer:

Answers 1. An amide linkage between the carboxyl group of one amino acid and the amine group of the other amino acid. 2. An ester is a compound formed from the reaction of a carboxylic acid and an alcohol. ( I apologise, I cant figure out number 3.. )

Answer:

diamonds

Explanation:

Diamond does not conduct electricity.  

• A form of carbon in which each of the atom of carbon is joined to four other atoms of carbon, giving rise to a giant covalent composition is a diamond.  

• Due to this, diamond is very robust and exhibits high melting point. Thus, is used to cut tools.  

• Diamond does not conduct electricity, due to the absence of delocalized electrons in the structure.  

Thus, diamond does not conduct electricity. Option d is correct.

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Answer:

Explanation: I can't give you the answer you with the sentence but i will help you the best i can

One qualitative measure of the strength of an acid or a base solution is the pH scale A logarithmic scale that relates the concentration of the hydrogen ion in solution.

There are 23 atoms of Fe in a 55.845 gram. As a result, after dividing our mass of 239 grams by the iron formula mass of 55.84 grams per bole, formol equals after calculation.

Use the millimeters to mole formula to calculate the molecular weight n, of a substance with a given mass, m, (in grams) accurately. n = m / M, where M is the substance's molar mass also known as gram-molecular weight. a substance's molecular weight expressed as a mass in grams. Example: NaCl salt weighs 58.44 grams per gram-mole. American Meteorological Society, copyright 2022.

Number of Avogadro = 6.023 × 10²³. The products of every chemical reaction are measured using the Avogadro number. 1 mole of atoms, molecules, or particles is equal to 6.023 x 1023. Calculating the number of molecules is as follows: mole number = quantity of material / mass of one mole.

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There are 23 atoms of Fe in a 55.845 gram. As a result, after dividing our mass of 239 grams by the iron formula mass of 55.84 grams per bole, formol equals after calculation.

Use the millimeters to mole formula to calculate the molecular weight n, of a substance with a given mass, m, (in grams) accurately. n = m / M, where M is the substance's molar mass also known as gram-molecular weight. a substance's molecular weight expressed as a mass in grams. Example: NaCl salt weighs 58.44 grams per gram-mole. American Meteorological Society, copyright 2022.

Number of Avogadro = 6.023 × 10²³. The products of every chemical reaction are measured using the Avogadro number. 1 mole of atoms, molecules, or particles is equal to 6.023 x 1023. Calculating the number of molecules is as follows: mole number = quantity of material / mass of one mole.

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Answer:

106g/mol

Explanation:

Mass of Na=2×23=46

Mass of C=12

Mass of O=3×16=48

Total mass of Na2CO3=106g/mol

Answer:

The answer is Protein.

Answer:

check the Ac so ya so ya so ya so ya so ya so ya

Answer:

Butter stored in a refrigerator is a solid. Sara should put a thermometer in the refrigerator for an hour and record this temperature.

Answer:

A Family Portrait

That element is NOT in the family. When we told you about families, we said that they were groups of elements that react in similar ways. Hydrogen is a very special element of the periodic table and doesn't belong to any family. While hydrogen sits in Group I, it is NOT an alkali metal.

Answer:

Explanation:

The chemical properties are so different and cannot be group into a family Hydrogen is the simplest, smallest and lightest of the elements. Unlike the other elements of the periodic table, the combination of properties it exhibits doesn't match any one single grouping or family.

Answer:

HE (helium)

Explanation:

Answer: Helium

Explanation: If you look at a periodic table noble gasses are on the far right side

Answer:

c Electrons are many thousand times smaller than the nucleus and negatively charged.

Explanation:

trust me slime

Answer:

c

Explanation:

its c

We need the structure (Refer to the attachment)

Answer:

The noble gases are the chemical elements in group 18 of the periodic table. They are the most stable due to having the maximum number of valence electrons their outer shell can hold. Therefore they rarely react with other elements since they are already stable

The therapist's suggestion most directly reflects a psychodynamic perspective.

The psychodynamic perspective, developed by Sigmund Freud and later expanded upon by other psychologists, focuses on the role of unconscious processes and early childhood experiences in shaping an individual's thoughts, emotions, and behaviors. Dissociative identity disorder (formerly known as multiple personality disorder) is seen through this lens as a defense mechanism that arises from unresolved conflicts and trauma. According to the psychodynamic perspective, dissociation and the development of multiple identities serve as a way for individuals to cope with and protect themselves from distressing or unbearable emotions and experiences, such as intense hatred or anger towards an abusive mother. The suggestion made by Midori's therapist suggests an interpretation rooted in psychodynamic principles, emphasizing the unconscious and the use of defense mechanisms.

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The flow of chilled water through the cooling coil is regulated by a control valve.

In HVAC systems, the flow of chilled water through the cooling coil is regulated by a device called a control valve. The control valve is responsible for adjusting the flow rate of chilled water based on the cooling demand of the system. It ensures that the right amount of chilled water is supplied to the cooling coil to maintain the desired temperature in the conditioned space.

The control valve is typically controlled by a building automation system or a thermostat. These devices monitor the temperature in the conditioned space and send signals to the control valve to open or close. When the temperature rises above the set point, the control valve opens to allow more chilled water to flow through the cooling coil, cooling the air. Conversely, when the temperature falls below the set point, the control valve closes to reduce the flow of chilled water.

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The flow of chilled water through the cooling coil is regulated by a control valve. This valve adjusts the flow rate based on the cooling needs of the system.

A thermostat or temperature sensor provides signals to the control valve, which opens or closes accordingly.

When the temperature exceeds the desired setpoint, the control valve opens, allowing more chilled water to pass through the cooling coil.

This increases cooling capacity and lowers the air or space temperature.

Conversely, the control valve closes when the temperature reaches or falls below the set point, reducing chilled water flow.

The control valve ensures precise temperature control and efficient cooling operation in the system.

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Answer:

The first person to go to the moon

Explanation:

Neil Armstrong was the first person !

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FALSE. Bent molecules do not have lone pair on the central atom.

Bent molecules is a kind of molecular geometry in which the central atom has two lone pairs of electrons and is associated with two bond pairs.

The molecular structure is also known as angular or V-shaped.

Thus, the statement "bent molecules do not have lone pair on the central atom"  is FALSE.

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The IHD for the given formula is 5. There could be five double bonds present in the molecule. There could be five rings present in the molecule.

To calculate the index of hydrogen deficiency (IHD) for the given formula C₇H₁₀NBRC₇H₁₀NBR, we need to determine the molecular formula's degree of unsaturation. The formula can be simplified to C₁₄H₂₀N₂BR₂, assuming all the atoms are bonded to each other.

The formula for calculating IHD is:

IHD = 0.5 × (2C + 2 + N - X - H)

Where:

C = number of carbon atoms

N = number of nitrogen atoms

X = number of halogen atoms (in this case, bromine, so X = 2)

H = number of hydrogen atoms

Let's calculate the IHD for C₁₄H₂₀N₂BR₂:

C = 14

N = 2

X = 2

H = 20

IHD = 0.5 × (2(14) + 2 + 2 - 2 - 20)

= 0.5 × (28 + 2 + 2 - 2 - 20)

= 0.5 × 10

= 5

Therefore, the IHD for the given formula is 5.

Based on the IHD value, we can determine the types of unsaturation that might be present in the molecule. Here are the possibilities:

Double Bonds (Alkenes): Each double bond contributes 1 to the IHD. So, there could be five double bonds present in the molecule.

Rings (Cyclic Structures): Each ring contributes 1 to the IHD. So, there could be five rings present in the molecule.

A Combination of Double Bonds and Rings: It is also possible to have a combination of double bonds and rings. For example, there could be three double bonds and two rings, or two double bonds and three rings, or any other combination that adds up to an IHD of 5.

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Adding a reagent dropwise is typically done to control the rate of the reaction and prevent it from proceeding too quickly or producing unwanted side reactions. If a large amount of the reagent is added at once, the reaction may proceed too quickly and may not be able to be observed or monitored accurately.

Furthermore, adding the reagent dropwise can allow for better mixing and distribution of the reagent in the reaction mixture, which can be important for achieving a complete reaction. If a large amount of the reagent is added all at once, it may not be evenly distributed throughout the mixture, leading to incomplete or non-uniform reactions.

Adding the reagent dropwise can also allow for better observation of the reaction as it occurs, allowing the observer to detect any changes or intermediate steps that may be missed if the reagent is added all at once. If the reagent is added all at once, it may be difficult to accurately determine the progress of the reaction and the identity of the products formed.

In summary, if the instruction to add the reagent dropwise is ignored and a large amount of the reagent is added at once, important observations may be missed, including changes in color, the formation of intermediate products, and the completion of the reaction. It is important to follow the instructions carefully to ensure that the reaction is observed and monitored accurately.

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Answer:

0.40M

Explanation:

no of moles=molarity×volume of solution in litre

Our current understanding of the atom is based on Dalton's early 19th-century idea of atomism, which was developed from meteorological investigations. John Dalton was just a meteorologist, an expert on color blindness, and a teacher, but he will be most widely recognized for creating the idea of atomism.

A scientist is someone who meticulously gathers data and uses it to develop theories, test those hypotheses, and further knowledge and understanding. Despite the fact that the name "scientist" predates Aristotle by more than two millennia, he is frequently referred to as the first scientist. He invented the methods of reasoning, observation, inquiry, and demonstration in Greece in the fourth century BC.

Because they provide specialized explanations for how the world functions, scientists play a crucial role in society. Science is a powerful tool for survival, despite the fact that it doesn't always provide us with joy, and humans have spent considerable time starting to figure out how to do both.

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The molar concentration of a 12% sodium chloride solution is approximately 2.05 M.

To determine the molar concentration of a 12% sodium chloride solution, we need to convert the given percentage concentration into molarity.

First, we need to understand that the percentage concentration refers to the mass of the solute (sodium chloride) relative to the total mass of the solution.

In this case, a 12% sodium chloride solution means that there are 12 grams of sodium chloride in 100 grams of the solution.

To convert this into molar concentration, we need to consider the molar mass of sodium chloride, which is 58.5 g/mol.

We can start by calculating the number of moles of sodium chloride in 12 grams:

Moles of sodium chloride = mass of sodium chloride / molar mass of sodium chloride

Moles of sodium chloride = 12 g / 58.5 g/mol = 0.205 moles

Next, we calculate the volume of the solution in liters using the density of the solution. Since the density is not provided, we assume a density of 1 g/mL for simplicity:

Volume of solution = mass of solution / density

Volume of solution = 100 g / 1 g/mL = 100 mL = 0.1 L

Finally, we calculate the molar concentration (Molarity) by dividing the number of moles by the volume in liters:

Molar concentration = moles of solute / volume of solution

Molar concentration = 0.205 moles / 0.1 L = 2.05 M

Therefore, the molar concentration of a 12% sodium chloride solution is approximately 2.05 M.


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Answer:

Examine the units: If the density is 1 g/mL, how many mL do you need to make 250 g?

X mL * 1 g/mL = 250 g

Solve for X

x mL = 250 g / 1 g/mL = 250 mL

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The volume of water = 250 L

\(density = \frac{mass}{volume}\)

Given, density = 1.0 g/L = 0.001 kg/L

           mass = 250 g = 0.25 kg

Putting the values in the equation

\(0.001 = \frac{0.25}{volume}\)

\(volume = \frac{0.25}{0.001}\)

\(volume = 250 L\)

Hence, the volume of the water is 250 L.

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OwO ^ ^ its A guys knowing cause i took the test

Answer:

C

Explanation:

cookware manufacturers who make pans out of steel only