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a)
b)
c)
d)

2.96 × 10²³ molecules is required if Alex drips hydrochloric acid onto a 5.9 g piece of magnesium in a single displacement reaction

According to this question, hydrochloric acid (HCl) reacts with magnesium metal (Mg) to produce magnesium chloride and hydrogen has as follows:

2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)

Where; Mg = 24g/mol

mole = 5.9/24

mole = 0.246mol of Mg

To convert mole to number of molecules, we multiply number of moles by 6.02 × 10²³ (Avogadro's no.)

Hence, number of molecules of HCl required is 0.492mol × 6.02 × 10²³

= 2.96 × 10²³ molecules of HClHCl

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Answer:

65.5J

Explanation:

ML=Q

ML=MC(change in temperature)

0.75 X 23000 =0.75 X 351 X C

C= 65.5J

The energy supplied to the lead to melt from 21°c to its melting point is 51521 Joules.

Specific heat is the amount of heat energy supplied to change the temperature of one unit mass of a substance by 1 °C. The SI unit of the specific heat capacity of a substance is J/Kg.

The mathematical expression for the specific heat capacity can be written as:

Q = mCΔT      Where C is the specific heat of the substance.

The specific heat capacity depends upon the starting temperature and is an intensive characteristic of the material.

Given, the melting point of the lead T₂ = 327.5° C

The initial temperature of the lead, T₁ = 21° C

The latent heat of the lead given, L = 230000 J/Kg K

The specific heat of the lead, C = 130 J/Kg K

The heat required to melt the lead from 12°C to 327.5 °C is :

Q = m× [C × (T₂ - T₁) + L ]

Q = 0.75 × [0.130 (327.5 - 21)  + 23000]

Q = 51521 J

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Answer:

ch3:-methanide

No2:-nitrogen dioxide

thank you and mark as brainliest if u find it helpful

I first converted the given grams of the reactants into moles, and then divided the moles by the coefficients in front of each of the reactant. The result with the smallest value will be the limiting reactant, and the value of CuO was the smallest, so it's the limiting reactant.

After figuring out which reactant is the limiting one, I took their given grams and converted it into moles, the divided it by the ratio of N2 to CuO (it's in the equation) to obtain the moles of N2, and then multiply it with the molar mass of N2 to get its mass in grams.

Answer:

Explanation:

418.4kj is the correct answer

Answer:

False because it is false

Answer:

See explanation

Explanation:

The dissolution of oxygen in water is exothermic. Hence, at higher temperature, less oxygen is dissolved in water.

If the chemist commits an error and records 27°C instead of 21°C, the dissolved oxygen concentration will be found to be lower than it should be at 27°C because dissolution of gases in water is exothermic.

Answer:

The median is also the number that is halfway into the set. To find the median, the data should be arranged in order from least to greatest. If there is an even number of items in the data set, then the median is found by taking the mean (average) of the two middlemost numbers.

I hope it helps

Answer:

NO3 has 3 atoms of oxygen in it per molecule (indicated by the subscript of 3) and (NO3)2 means you have 2 NO3 molecules, meaning you double the subscript to get 6 oxygen atoms

Mno4- chemical name is permanganate

Answer:

Pure water has an acidity of about 7 on the pH scale. -is a chemical property of pure water. Pure water has an acidity of about 7 on the pH scale

Answer: không màu , không mùi không vị

Explanation:

Answer:

false, it is not an example of facilitated diffusion

Answer:

Explanation:

When a drop of ink added into the water gradually moves in the whole quantity of water due to this entire water turns into blue color. This is nothing but the diffusion of ink particles into the water molecules. This is because water, as well as ink molecules, are in random motion due to the motion of ink substance.

Explanation:

the difference between temperature and thermal energy are as follow ,

• The thermal energy, or heat, of an object is obtained by adding up the kinetic energy of all the molecules within it. Temperature is the average kinetic energy of the molecules.

Answer:

D

Explanation:

Desalination

Removing salt from sea water is known as desalination

There are two types of electrostatic forces: interatomic or intermolecular.

In this case the type of force that prevents ice cubes from adopting the shape of their container​ is intermolecular.

Within a molecule, the atoms are held together by interatomic forces. These forces are what determine the chemical properties of substances because it is these forces that must be overcome for a chemical change to occur.  

In summary, intermolecular forces are characterized by holding more than one molecule together.

On the other side, intermolecular forces act on different molecules or ions and cause them to attract or repel each other, causing different physical states in chemical compounds.

Therefore, the intermolecular forces are responsible for the existence of the liquid and solid state (between  the molecules of a gas do not exist intermolecular forces.).

Then ice cubes do not ocuppy the shape of thir container because it is in solid state, existing intermolecular force between molecules to maintain said physical state.

In summary, the type of force that prevents ice cubes from adopting the shape of their container​ is intermolecular.

Learn more about intermolecular forces:

The compound that has been soluble in water will be LiCl. Thus option E is correct.

The compounds that form stable bonds in water and are easy to dissociate are soluble in water. Generally, ionic compounds are easily soluble in water.

It has been an ionic compound, but the dissociation of AgCl will simultaneously form AgCl again making the compound insoluble in water.

It has been a covalent compound, thus it has been insoluble in water.

The compound is covalent in nature, thus it has been hard to dissociate in water.

The copper in the compound has been hard to dissolve and precipitate in the solution.

It has been an ionic compound and can be easily dissociated in the water.

Thus the compound that has been soluble in water will be LiCl. Thus option E is correct.

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Answer:

The r.a.m. value is used to determine how many isotopes an element has.

Explanation:

Answer:

Methane and chlorine

If a mixture of methane and chlorine is exposed to a flame, it explodes - producing carbon and hydrogen chloride. This is not a very useful reaction! The reaction we are going to explore is a more gentle one between methane and chlorine in the presence of ultraviolet light - typically sunlight. This is a good example of a photochemical reaction - a reaction brought about by light.

CH4+Cl2+energy→CH3Cl+HCl(3.4.2)

The organic product is chloromethane. One of the hydrogen atoms in the methane has been replaced by a chlorine atom, so this is a substitution reaction. However, the reaction doesn't stop there, and all the hydrogens in the methane can in turn be replaced by chlorine atoms.

Substitution reactions happen in which hydrogen atoms in the methane are replaced one at a time by chlorine atoms. You end up with a mixture of chloromethane, dichloromethane, trichloromethane and tetrachloromethane.

I hope this help you!:)

Explanation:

Answer: 10.0 L

Explanation:

not 100% sure but I think its C

The correct name for the given alkane molecule is 2,2-dimethylpropane. (Option C)

The given alkane molecule is composed of three carbon atoms. The central carbon atom is bonded to two methyl groups (CH₃) on either side. This results in a branched structure where the methyl groups are attached to the same carbon atom.

According to the rules of IUPAC nomenclature, the prefix "2,2-" indicates that the methyl groups are attached to the second carbon atom in the main chain. The parent chain, which consists of three carbon atoms, is named propane. Since there are two identical methyl groups attached to the second carbon atom, the compound is named 2,2-dimethylpropane.

Hence, the name of the given alkane molecule is 2,2-dimethylpropane.

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Answer:

A

Explanation:

because the species being oxidized shares electrons with the species that is reduced.making the oxidized element positively charged and the reduced element negatively charged.

I hope this helps

Alphabet:B. the species being oxidized takes electron from some other

Answer:

U are a fool

Explanation:

Because you didn't even asked a question

Answer:

k.

Explanation:

The force exerted on the container by the particles of the matter is called pressure. The tank containing oxygen gas at 2.551 atm will have a pressure of 1939 mm Hg.

Pressure is the property used to estimate the force experienced by the system due to the liquid or the gas held in it. The pressure of the gas can be calculated by the ideal gas and force and area.

The pressure is created due to the collision of the particles of the gases and liquids on the wall perpendicularly. It is estimated in Pascal (Pa) as the standard unit along with atm and mmHg.

It is known that 1 atm = 760 mm Hg

Given,

The pressure of oxygen gas = 2.551 atm

Using the conversion factor the pressure from atm to mm Hg is calculated as,

1 atm = 760 mm Hg

2.551 atm = (2.551 atm × 760 mm Hg) ÷ 1 atm

= 1938.76 mmHg

Therefore, 1939 mm Hg is the pressure of the oxygen gas.

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Answer:

It is prepared small amounts of hydrogen cloride for uses in the lab.

It can be  "generated in an HCl generator by dehydrating hydrochloric acid with either sulfuric acid or anhydrous calcium chloride."

The correct answer is C. square planar

According to the Valence Shell Electron Pair Repulsion Theory(VSEPR), The shape of a molecule depends on the number of electron pairs in the molecule.

VSEPR theory was first coined by Gillespie  and Nyhlom in 1957 as an improvement over the Sidgwick - Powell theory.

According to this theory, the shape of a molecule is determined by the number of electron pairs that surround the valence shell of the central atom in the molecule.  The electron pairs are positioned as far apart in space as possible to minimize repulsion of electron pairs.

However, the presence of lone pairs distorts the shape anticipated for the molecule on the basis of VSEPR.

For a molecule having six electron pairs, an octahedral geometry is expected(electron domain geometry). However, the presence of two lone pairs which are positioned at opposite side of the four single bonds leads to an observed square planar molecular geometry.

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Answer:

square planar

Explanation:

Explanation:

to find the number of moles for tetracycline you use the formula,

number of moles=mass/molar mass

the mass is given in the question which is 71.9g and the molar mass is 444.43(you find I by adding the number of atoms for each element in the compound,12×22+1×24+14×2+16×8)

n=71.9g/444.43

=0.16g/mol

I hope this helps

Answer:

In both cases, the gas evolved is H2. When calcium reacts with water the heat evolved is not suffcient for hydrogen to catch fire. On the other hand, sodium metal reacts with water violently and in this case a lot of heat is evolved which is sufficient for hydrogen to catch fire.

Explanation:

may this answer is helpful for you

Hydrogen

The reaction is given by

[tex]\boxed{\sf {Ca\atop Calcium}+{H_2O\atop Water}\longrightarrow {Ca(OH)_2\atop Calcium\:Hydroxide}+{H_2\atop Hydrogen}}[/tex]

Balanced equation:-

[tex]\boxed{\sf {Ca\atop Calcium}+{2H_2O\atop Water}\longrightarrow {Ca(OH)_2\atop Calcium\:Hydroxide}+{H_2\atop Hydrogen}}[/tex]