Which substance has Delta.Hf defined as 0 kJ/mol? H2O (s) Ne (l) F2 (g) CO2 (g)

Answer:

The most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Explanation:

The mass, in percentage, of eah isotope of Calcium is their fractional composition multiplied by 100:

40Ca-0.96941*100 =  96.941% of ⁴⁰Ca

42Ca-0.00647*100 = 0.647% of ⁴²Ca

43Ca-0.0013*100 = 0.13% of ⁴³Ca

44Ca-0.02086*100 = 2.086% ⁴⁴Ca

46Ca-0.00004*100 = 0.004% ⁴⁶Ca

48Ca-0.00187*100 = 0.187% of ⁴⁸Ca

That means the most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Answer:

yes

Explanation:

cos of high electron transfer

Protons: charge: +1 // mass: 1 // location: nucleus

Neutrons: charge: 0// mass: 1 // location: nucleus

Electrons: charge: -1// mass: 0// location: orbitals

Answer:

As the Mentos candy sinks in the bottle, the candy causes the production of more and more carbon dioxide bubbles, and the rising bubbles react with carbon dioxide that is still dissolved in the soda to cause more carbon dioxide to be freed and create even more bubbles, resulting in the eruption

Answer:

the answer is H ..............

Answer:

0.348 L

Explanation:

Step 1: Given data

Step 2: Calculate the volume of the concentrated solution

We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the concentrated solution using the dilution rule.

C₁ × V₁ = C₂ × V₂

V₁ = C₂ × V₂ / C₁

V₁ = 1.07 M × 2.11 L / 6.49 M = 0.348 L

Answer:

B. 4 ham slices

Explanation:

A chemical reaction involves one or more substances known as reactants combining chemically to give one or more substances known as products.

Reactants in chemical reactions combine in definite mole or mass ratios to give products. Therefore, when one substance is present in excess of what is required to combine with another to form products, that substance is known as the excess reagent. The other substance which is present in a smaller amount and which when used up, the reaction stops is known as the limiting reagent.

From the illustration of the sandwiches in the question, the recipe for one sandwich represents the chemical equation of a reaction. The equation form is given below:

2 cheese slices + 1 ham slice + 2 bread slices ---> 1 sandwich

The ratio of the reactant is 2 : 1 : 2

From the available ingredients, 12 cheese slices, 10 ham slices, 12 bread slices.

12 cheese slices will require 6 ham slices and 12 bread slices to produce 6 sandwiches.

However, since there are 10 ham slices, 4 ham slices will be left over unused. This is the excess or leftover reactant.

Answer:

B. 4 ham slices

Explanation:

Got it right on the test

Explanation:

this explanation may help u to understand:)

Answer:

A change is called irreversible if it cannot be changed back again. For example you cannot change a cake back into its ingredients again. Irreversible changes are permanent.

Explanation:

Hope this helps!! :))

Answer:

?

Explanation:

Answer:

Noble gases are a  set of elements in the periodic table because they don't naturally bond with other elements. *Examples ...Helium; Neon; Radon; Xenon; Argon etc

Explanation:

theyre noble gases.

Answer:

the Rhyniognatha hirsti

Explanation:

at age 400 million years old

Answer:

A

Explanation:

Answer:

the correct answer is option C. Na

Answer:

1.104 J/g°C

Explanation:

Using Q = m × c × ∆T

Where;

m = mass of substance (g)

c = specific hear capacity (J/g°C)

∆T = change in temperature (°C)

For a colorimeter,

Q(water) = - Q(metal)

m. c. ∆T (water) = - m. c. ∆T (metal)

According to the information provided;

For water:

m = 28.0g

c = 4.184 J/g°C

∆T = (21.23 - 19.73°C)

For the metal:

m = 2.05g

c = ?

∆T = (21.23 - 98.88°C)

m. c. ∆T (water) = - m. c. ∆T (metal)

[28 × 4.184 × (21.23 - 19.73°C)] = -[2.05 × c × (21.23 - 98.88°C)]

[117.152 × 1.5] = -[2.05 × c × (-77.65)]

175.728 = -[-159.1825c]

175.728 = 159.1825c

c = 175.728 ÷ 159.1825

c = 1.104

c = 1.104 J/g°C

Answer:

Lake Treatment

Explanation:

Sulphuric dioxide produced by industries and released into the atmosphere returns as acid rain or sulphuric acid. In lakes impacted by acid rain, such as in Ontario, Canada, the application of alkalis dropped by airplanes can control and neutralize the water's pH level.

Answer:

[tex][Cl_2]=[Br_2]=0.856M[/tex]

[tex][BrCl]=0.229M[/tex]

Explanation:

Hello there!

In this case, for this chemical equilibrium problem, it turns out possible for us to solve for the equilibrium concentrations by firstly setting up the equilibrium expression:

[tex]Keq=\frac{[BrCl]^2}{[Cl_2][Br_2]}[/tex]

Thus, by plugging in an ICE chart, in terms of x (reaction extent), we can write:

[tex]7.20=\frac{(2x)^2}{(0.200-x)^2}[/tex]

And could be solved for x as follows:

[tex]\sqrt{7.20} =\sqrt{\frac{(2x)^2}{(0.200-x)^2} } \\\\2.68=\frac{2x}{0.200-x} \\\\x=0.1146M[/tex]

Therefore, the equilibrium concentrations turn out to be:

[tex][Cl_2]=[Br_2]=0.200M-0.1146M=0.856M[/tex]

[tex][BrCl]=2*0.1146M=0.229M[/tex]

Regards!

Answer: 88 grams

Explanation:

Answer: See explanation

Explanation:

Vacuum filtration is referred to as a fast filtration technique that is used in the separation of solids from liquids. It is also used to collect a desired solid. It basically uses a side-arm flask and a Buchner funnel.

Based on the question, the techniques that should be used to ensure a quantitative separation goes thus:

• Wet the filter paper before the mixture is poured into the filter funnel.

• Then, carefully rinse the flask with a little amount of water into the filter funnel.

• After that, the solid on the filter paper should be washed the with a small amount of water.

• Finally, Dry the solid on the filter paper when the separation is done.

Fluids are liquid and gases. They take the shape of their containers. They are called fluids because of their ability to flow.

Answer: Rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] >  [tex]CBr_{3}COOH[/tex] >  [tex]CH_{3}COOH[/tex].

Explanation:

More readily a substance is able to donate a hydrogen ion more will be its acidic strength. Hence, stronger will be the acid.

More is the electronegativity of atoms attached to the acid more easily it will donate a proton. Hence, more will be its acidic strength.

Chlorine is more electronegative in nature as compared to bromine. So,

[tex]CCl_{3}COOH[/tex] is more acidic than [tex]CBr_{3}COOH[/tex].

Since there is no electronegative group attached to [tex]CH_{3}COOH[/tex] so it is least acidic than [tex]CCl_{3}COOH[/tex] and [tex]CBr_{3}COOH[/tex].

Thus, we can conclude that rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] >  [tex]CBr_{3}COOH[/tex] >  [tex]CH_{3}COOH[/tex].

Answer:

True

Explanation:

Hydrogen bonding is a type of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.

We define the term ''hydrogen bond donor'' as the molecule that supplies the hydrogen atom in the hydrogen bond.

Hence, it is true that the molecule or ion that donates the hydrogen in a hydrogen bond is a hydrogen bond donor

Answer:

B - The high temperature makes the gas molecules spread apart according to Charles's law because this law describes how a gas will behave at constant pressure.

Explanation:

Charle's Law describes the relationship between temperature and volume, where increased temperature leads to increased volume. When volume is increased, that means the gas molecules are more spread apart and have more random motion. Therefore, the answer is B.

The high temperature causes the gas molecules to spread apart according to Charles's law because explain how a gas, behave at constant pressure.

The physical principle called Charles' law which  states that the volume of a gas equals a constant value many by its temperature as measured on the Kelvin scale.

Volume regaled by a clinched amount of gas is directly proportional to its temperature and pressure if remains steady.

Thus, option "B" is correct, the volume of a gas equals a constant value.

To learn more about Charles law click here:

https://brainly.com/question/14842720

Answer:

False

Explanation:

Roman numerals are seen in the names of several compounds. They often appear immediately after the name of central atom in the molecule.

These Roman numerals are used to depict the oxidation state of the central atom in the molecule and not to show how many of that ion appear in the formula.

For instance, in carbon IV oxide, the Roman numeral IV shows that the central atom in the compound-carbon is in the +4 oxidation state.

Answer:

4⁺

Explanation:

Germanium (Ge) has an atomic number of 32 and belongs to group 14 on the periodic table. Germanium has an electronic configuration of [Ar] 3d¹⁰ 4s² 4p². There exist 32 electrons in its neutral atom. In fluorescent lights, germanium is utilized as a component of both alloys and phosphorus.

The electrons in the atom's outer shell are known as its valence electrons.

Thus, at the ground state, the outer shell of the Germanium atom has 4 electrons.

Answer:

Yes.

Explanation:

Yes, enough folic acid in the body by the early weeks of pregnancy helps to prevent spina bifida. The body of woman uses folate during the pregnancy which produces red and white blood cells that help your baby to grow. Folate also lowers the risk of neural tube defect (NTD) in the unborn baby. Neural tube defect (NTDs) are the serious birth defects that greatly affect the spinal cord, brain and skull of the baby.

Answer:

turtle

Explanation:

they are slow and they take there time

Answer: As temperature increases, the number of collisions increases and the energy of the collisions increases.

Explanation:

According to collision theory, for a reaction to take place it is necessary to have collisions between the reacting species or atoms.

A collision will only be effective if species coming together have a certain minimum value of internal energy equal to the activation energy of the reaction.

More is the number of collisions taking place in a chemical reaction more will be the kinetic energy of its molecules. As kinetic energy is the energy acquired due to motion of atoms or a substance.

Also, collisions increases with increase in temperature as:

[tex]K.E = \frac{3}{2}kT[/tex]

Kinetic energy is directly proportional to temperature. So, more is the temperature more will be energy of molecules.

Thus, we can conclude that as temperature increases, the number of collisions increases and the energy of the collisions increases.

Answer:

% yield =  82.5%

Explanation:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

Our reactants are:

Our products are:

We do not have information about moles of reactants, but we do know the theoretical yield and the grams of product, in this case Cl₂O, we have produced.

Percent yield = (Yield produced / Theoretical yield) . 100

Theoretical yield is the mass of product which is produced by sufficent reactant. We replace data:

% yield = (0.71 g/0.86g) . 100 = 82.5%

The percent % yield =  82.5%

The balanced chemical equation will be:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

The reactants participating in this reaction are: HgO and Cl₂

The products so formed are: HgCl₂ +  Cl₂O

[tex]\text{ Percent yield} = \frac{\text{Yield produced}}{\text{Theoretical yield}} *100[/tex]

The theoretical yield is the maximum possible mass of a product that can be made in a chemical reaction.

[tex]\text{Percent yield}= \frac{0.71 g}{0.86g} * 100 \\\\\text{Percent yield}= 82.5\%[/tex]

Thus, the percent yield is 82.5%.

Learn more:

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