Disadvantages of modern periodic table?
​

Answer:

physical properties include melting point, boiling point, strength, and malleability.

Explanation:

Answer:

Metal properties.

Explanation:

metal has its fix point to melt and boil expect mercury because it doesn't have its own fix point of melting or boiling, strength- if metal is heated then it can be strength and we can give it shape by heating

Answer: The volume of the gas is 178.76 L

Explanation:

The ideal gas equation is given as:

.......(1)

where

P = pressure of the gas = 675 torr

V = volume of gas = ?

n = number of moles of gas = 6.45 moles

R = Gas constant = 62.36 L.torr/mol.K

T = temperature of the gas = [tex]27^oC=[27+273]K=300K[/tex]

Putting values in equation 1, we get:

[tex]675torr\times V=6.45mol\times 62.36L.torr/mol.K\times 300K\\\\V=\frac{6.45\times 62.36\times 300}{675}=178.76 L[/tex]

Hence, the volume of the gas is 178.76 L

Answer:

Compound X has the formula C8H14.

X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethyl cyclohexane. Treatment of X with ozone followed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O). What is the structure of X?

Explanation:

The degree of unsaturation in the given molecule C8H14 is:

DU=(Cn+1)-Hn/2-Xn/2+Nn/2

where,

Cn=number of carbon atoms

Hn=number of hydrogen atoms

Xn=number of halogen atoms

Nn=number of nitrogen atoms

C8H14:

DU=(8+1)-14/2

=>DU=9-7 =2

Hence, the given molecule will have either two double bonds or one double bond and one ring or two rings.

X reacts with one molar equivalent of hydrogen in the presence of a palladium catalyst to form a mixture of cis- and trans-1,2-dimethylcyclohexane.

This indicates that the molecule X has one double bond and one ring that is cyclohexane ring.

Treatment of X with ozone follwed by zinc in aqueous acid gives a ketone plus formaldehyde (CH2=O).

So, the molecule has a ring and double bond CH2.

Based on the given data the structure of compound X is shown below:

The reaction sequence is shown below:

dont mind me here for the points

Answer:

25%

Explanation:

Cystic fibrosis is a recessive allele, meaning that the child must be aa to suffer the symptoms. Only 1/4 of the paired alleles is aa, so the probability of getting cystic fibrosis would be 25%.

Answer:

To convert 100.0 g of water at 20.0 °C to steam at 100.0 °C requires 259.5 kJ of energy. Let me know if this helped?

Answer:

the name for NO is nitrogen monoxide

Answer:

(Basic )

Real

These are formed in the front side of the mirror.

Virtual

These are assumed to be formed at the backside of the mirror.

Type of lens used

Converging(real)

Diverging(virtual)

Image reception

Image can be appeared on a screen.(Real)

Image appears to be on the mirror or lens itself.

Interaction of light rays Actual Imaginary(Virtual)

Appearance of image

Inverted(Real)

Erect(Virtual)

Formed by

Concave mirror and convex lens.(Real)

Plane, convex mirror and concave lens.(Virtual)

Example

Image on the theater screen.(Real)

Reflection of any object or body on plane mirror.(Virtual)

Answer:

21.12 grams

Explanation:

Using the given number of hydrogen moles, we calculate the number of carbon atoms, keeping in mind that there are 3 carbon moles per hydrogen mol:

4.70 mol H * [tex]\frac{3molC}{8molH}[/tex] = 1.76 mol C

Finally we convert 1.76 moles of carbon into grams, using its molar mass:

1.76 mol * 12 g/mol = 21.12 g

The question is incomplete, the complete question is:

When aqueous solutions of NaCl and [tex]Pb(NO_3)_2[/tex] are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M NaCl is mixed with an excess of an aqueous solution of

Answer: The mass of lead chloride produced is 1.96 g

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)

Given values:

Molarity of NaCl = 0.1000 M

Volume of the solution = 140.7 mL

Putting values in equation 1, we get:

[tex]0.1000=\frac{\text{Moles of NaCl}\times 1000}{140.7}\\\\\text{Moles of NaCl}=\frac{0.1000\times 140.7}{1000}=0.01407mol[/tex]

The chemical equation for the reaction of NaCl and lead nitrate follows:

[tex]Pb(NO_3)_2(aq)+2NaCl(aq)\rightarrow PbCl_2(s)+2NaNO_3(aq)[/tex]

By the stoichiometry of the reaction:

If 2 moles of NaCl produces 1 mole of lead chloride

So, 0.01407 moles of NaCl will produce = [tex]\frac{1}{2}\times 0.01407=0.007035mol[/tex] of lead chloride

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(2)

Molar mass of lead chloride = 278.1 g/mol

Plugging values in equation 2:

[tex]\text{Mass of lead chloride}=(0.007035mol\times 278.1g/mol)=1.96g[/tex]

Hence, the mass of lead chloride produced is 1.96 g

Answer:

Using Newman projections, draw the most stable conformation for each of the following compounds.

(a) 3-methyl pentane, viewed along with the C2-C3 bond.

(b) 3,3-dimethyl hexane, viewed along with the C3-C4 bond.

Explanation:

(a) The structure of 3-methyl pentane is shown below:

In Newman projection, the most stable conformation is staggard conformation.

In staggard conformation, the torsional strain is very less compared to eclipsed conformation.

(b)3,3-dimethyl hexane, viewed along with the C3-C4 bond.

Answer:

See explanation

Explanation:

In writing the electron configuration of atoms, the core electrons are those electrons that occur in the inner shells. They do not participate in chemical reaction.

The valence electrons are those electrons that occur on the outermost shell of an atom and does participate in chemical reaction.

For Xe, the core electrons are; 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 while the valence electrons are; 5s25p6

For Ca, the core electrons are; 1s2 2s2 2p6 3s2 3p6 while the valence electrons are 4s2.

Hence, there are 18 core electrons and 2 valence electrons for Ca and 46 core electrons for Xe and 8 valence electrons

1 mole KOH give 1 mole KCl

so 12.5 will give 12.5 mole of KCl

we know that 1 mole of kcl is equal to 74 grams

so 12.5 mole have

12.5 × 74= 926 grams

Answer:

Let’s break down all the steps in the following SN1 reaction looking at the energy diagram: Step Breaking the C – LG bond. In this rate-determining step, a carbocation intermediateis formed: Step A nucleophilic attack.The carbocation is highly electron-deficient and the nucleophile attacks as a Lewis base usin…

Image

Explanation:

Answer:

111.44 g

Explanation:

We'll begin by calculating the volume of the solvent. This can be obtained as follow:

Mass of solvent = 21 g

Density of solvent = 0.865 g/mL.

Volume of solvent =?

Density = mass /volume

0.865 = 21 /volume of solvent

Cross multiply

0.865 × volume of solvent = 21

Divide both side by 0.865

Volume of solvent = 21 / 0.865

Volume of solvent = 24.28 mL

Next, we shall determine the volume of the solid. This can be obtained as follow:

Volume of solvent + solid = 80.0 mL.

Volume of solvent = 24.28 mL

Volume of solid =?

Volume of solid = (Volume of solvent + solid) – (Volume of solvent)

Volume of solid = 80 – 24.28

Volume of solid = 55.72 mL

Finally, we shall determine the mass of the solid. This can be obtained as follow:

Density of solid = 2.00 g/mL.

Volume of solid = 55.72 mL

Mass of solid =.?

Density = mass / volume

2 = mass of solid / 55.72

Cross multiply

Mass of solid = 2 × 55.72

Mass of solid = 111.44 g

Therefore, the mass of the solid is 111.44 g

Answer:

[Na₂CO₃] = 0.15 M

Explanation:

Molarity is a type of concentration.

It is useful for solutions, to say how many moles of solute are contained in 1L of solution.

We can also say, that molarity are the mmoles of solute in 1 mL of solution.

In this case, our solute is the Na₂CO₃.

We convert mass to moles: 0.79 g . 1 mol / 106g = 7.45×10⁻³ moles

We convert moles to mmoles:  7.45×10⁻³ mol . 1000 mmol / 1mol = 7.45 mmol

M = mmol / mL

M = 7.45 mmol / 50 mL = 0.15 M

Option A is the right answer.

Explanation:

Aromatic nitrogen bonded to hydrogen, as found in pyrrole must be represented as [nH] ; thus imidazole is written in SMILES notation as n1c[nH]cc1 . When aromatic atoms are singly bonded to each other, such as in biphenyl, a single bond must be shown explicitly: c1ccccc1-c2ccccc2 .

Explanation:

Neutralization is the reaction between an acid and a base, producing a salt and a neutralized base. A strong acid yields a weak conjugate base (A–), so a strong acid is also described as an acid whose conjugate base is a much weaker base than water.

Answer:

[tex]m_{H_2O}=73.0gH_2O[/tex]

Explanation:

Hello there!

In this case, since the formation of water from hydrogen and oxygen is:

[tex]2H_2+O_2\rightarrow 2H_2O[/tex]

Whereas we find a 2:2 mole ratio of hydrogen to water. In such a way, by using the Avogadro's number, the aforementioned mole ratio and the molar mass of water (18.02 g/mol), we obtain the following grams of water product:

[tex]m_{H_2O}=2.44x10^{24}molec*\frac{1molH_2}{6.022x10^{23}molec}*\frac{2molH_2O}{2molH_2}*\frac{18.02gH_2O}{1molH_2O}\\\\ m_{H_2O}=73.0gH_2O[/tex]

Regards!

Answer:

if it is pure, the substances is either an element or a compound. if a substance is not chemically pure, it is either a heterogeneous mixture or a homogeneous mixture. if its composition is uniform throughout, it is a homogeneous.

Answer:

Explanation:

Bromination of allylic compounds occurs when hydrogen atoms from neighboring double bonds are replaced. As a result, there are four (4) potential bromination products, as seen in the figure below.

NBS, also known as N-Bromo succinimide, is employed as a replacement for Br2 in certain instances. The benefit of NBS is that it produces a reduced level concentration for Br2, which means that bromination of the double bond isn't competitive. As soon as Br2 has been produced, the reaction continues in the same way as the remaining free-radical halogenation reactions.

Answer:

[tex]2.02gH_2[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to to calculate the mass of hydrogen gas by firstly setting up the undergoing chemical reaction:

[tex]2H_3PO_4+3Ca\rightarrow Ca_3(PO_4)_2+3H_2[/tex]

Thus, we apply the following stoichiometric setup, whereas the atomic mass of calcium is 40.08 g/mol, that of hydrogen is 2.02 g/mol and the mole ratio of these two substances is 3:3:

[tex]40.08gCa*\frac{1molCa}{40.08gCa}*\frac{3molH_2}{3molCa}*\frac{2.02gH_2}{1molH_2} \\\\=2.02gH_2[/tex]

Regards!

Answer:

53.2 mL

Explanation:

As this problem deals with the neutralization of a strong monoprotic acid and a strong base, we can solve it by using the following formula:

Where in this case:

We input the data:

And solve for Vb:

Answer:

5-Ethyl3-Methyloctane

Explanation:

Step in the naming of organic compound

Step 1: Take the longest continous carbon chain as the root hydrocarbon and name it according to the number of carbon atoms it contains, adding appropriate suffix to indicate the principal substituent group

Step 2:  Number the carbon atoms in the root hydrocarbons from the end which give the lowest number to the suffix, and then the prefix

Step 3:  Indicate other substituents by prefixes proceed by numbers to show their positions on the carbon chain

Applying the step above,

The longest carbon chain is  8, and the fuctional group is the single chain (alkane),

5-Ethyl3-Methyl,octane

Answer:

Fission reaction occurs.

Explanation:

When a radioactive atom undergoes a nuclear decay event, spontaneous fission reaction occurs, the decaying nucleus undergoes a transformation in  the change in the number of protons in the nucleus. The fission process produces gamma photons, and releases a very large amount of energy. After the radiation stops, a stable element is obtained whereas the energy is released in the surrounding.

Answer:

A wave character exhibited by all particles

Explanation:

The central idea in quantum mechanics is the paradox of wave-particle duality. In quantum mechanics, all particles are believed to also exhibit wavelike characters.

The electron is assumed to behave as a wave hence its position can not be precisely determined according the Heisenberg's uncertainty principle.

These are the underlying postulates that informed Erwin Schrödinger's wave mechanical model of the atom.

Hence, the basic postulate of quantum mechanics is that a wave character is exhibited by all particles.

Answer:

The chemical symbol for Bismuth is Bi. Electron Configuration and Oxidation States of Bismuth. Electron configuration of Bismuth is [Hg] 6p3. Possible oxidation states are +3,5.

Answer: The given electronic configuration is long hand notation.

Explanation:

Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.

Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.

The given electronic configuration of potassium (K):  

The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.