1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride ? atoms of boron.

2. How many MOLES of fluorine are present in 5.35*1022 molecules of boron trifluoride ? moles of fluorine.​

A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).

Answer:

Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.

Answer:

The average atomic mass includes all of the isotopes of that atom which exist in nature. Almost all elements have at least two isotopes which naturally occur. Recall that isotopes are atoms with the same atomic number (protons), but a different number of neutrons.

Answer:

Explanation:

Because you only have one repeat unit, n=1. 2n-1 becomes 2(1)-1 which is equal to one, meaning one molecule of H2O is produced, as is shown by the top condensation polymerisation reaction.

If you had two repeat units, n=2 so 2n-1=3. Three H2O molecules are produced because you would need two molecules of each reactant so three condesation reactions would occur and three molecules of H2O would be released.

Answer: The [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].

Explanation:

Given: [tex][Ag^{+}] = 1.3 \times 10^{-4} M[/tex]

The reaction equation will be written as follows.

[tex]Ag_{2}CrO_{4} \rightleftharpoons 2Ag^{+} + CrO^{2-}_{4}[/tex]

This shows that the concentration of [tex]CrO^{2-}_{4}[/tex] is half the concentration of [tex]Ag^{+}[/tex] ion. So,

[tex][CrO^{2-}_{4}] = \frac{1.3 \times 10^{-4}}{2}\\= 0.65 \times 10^{-4} M[/tex]

The expression for [tex]K_{sp}[/tex] of this reaction is as follows.

[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}][/tex]

Substitute values into the above expression as follows.

[tex]K_{sp} = [Ag^{+}]^{2}[CrO^{2-}_{4}]\\= (1.3 \times 10^{-4})^{2} \times 0.65 \times 10^{-4}\\= 1.1 \times 10^{-12}[/tex]

Thus, we can conclude that the [tex]K_{sp}[/tex] of [tex]AgCrO_{4}[/tex] is [tex]1.1 \times 10^{-12}[/tex].

Answer:

no lo se yo hablo en español no en ingles

Answer:

[tex]\boxed {\boxed {\sf 0.601 \ g \ As}}[/tex]

Explanation:

We want to convert atoms of arsenic to mass in grams. We have to complete 3 steps.

The first step is converting atoms to moles. We use Avogadro's Number for this. This number is 6.022*10²³ and it is the number of representative units (molecules, atoms, etc.) in 1 mole of a substance. In this problem, the particles are atoms of arsenic. So, 1 mole of arsenic contains  6.022*10²³ atoms of arsenic. Use this information to make a ratio.

[tex]\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

Multiply by the number of atoms provided in the problem: 4.83 × 10²¹

[tex]4.83 *10^{21} \ atoms \ As *\frac{1 \ mol \ As}{{6.022*10^{23} \ atoms \ As} }[/tex]

The units of atoms of arsenic (atoms As) cancel.

[tex]4.83 *10^{21} *\frac{1 \ mol \ As}{{6.022*10^{23}} }[/tex]

Condense into 1 fraction.

[tex]\frac{4.83 *10^{21} }{{6.022*10^{23}} } \ mol \ As[/tex]

[tex]0.008020591166 \ mol \ As[/tex]

The next step is converting moles to grams. We use the molar mass for this, which is provided. There are 74.92 grams of arsenic in 1 mole of arsenic, so we can make another ratio.

[tex]\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

Multiply by the number of moles we calculated.

[tex]0.008020591166 \ mol \ As*\frac {74.92 \ g\ As}{ 1 \ mol \ As}[/tex]

The units of moles of arsenic (mol As) cancel.

[tex]0.008020591166 *\frac {74.92 \ g\ As}{ 1}[/tex]

[tex]0.6009026901 \ g \ As[/tex]

The original measurement of atoms (4.83 × 10²¹ ) has 3 significant figures, so our answer must have the same.

For the number we calculated, that is the thousandth place. The 9 in the ten-thousandth place (0.6009026901) tells us to round the 0 to a 1.

[tex]0.601 \ g \ As[/tex]

There are approximately 0.601 grams of arsenic.

Answer:

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

Or

Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

Answer:

Then, at some point, these higher energy electrons give up their "extra" energy in the form of a photon of light, and fall back down to their original energy level.

Explanation:

When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital.

Answer:

measurements are important to do calculations to get correct results and without them scientists cannot form theories

Answer:

If there were multiple products, we can take each product and mixed with a sample of a pure compound that we suspect might be the same as the product. Then, we taking the melting point of this mixture that contains one of our product and pure sample. Then, we can observe the change in melting point, if there is no change in melting point or the melting stays in the same range of the pure compound. Then, the that product along with the pure sample are actually the same compound, not a mixture of two compounds. However, if the melting point for our pure sample compound changed or didn't stay in the same range after the mixing with on of our products. then we can conclude that this product and the pure sample are completely different compound, and indeed they are a mixture.

Answer:

Hydrogenation

Explanation:

Look up the definition to confirm

Answer: Solve problems

Answer:c

Explanation: atoms make matter

Atoms are the basic building blocks of matter. The correct option is C.

Atoms are the basic unit and building block of matter. They are the smallest unit, but they can be divided. They do not emit charge on dividing into the further, the smallest parts.

Atoms are further divided into electrons, protons, and neutrons. They are the charged particles that revolve in the shell of the atom. A nucleus is also present in the between of the atom.

Atoms are considered the building blocks of matter, as all matter is made up of many atoms. The configuration of the atom defines the state of matter.

Thus, the correct option is C. The basic building blocks of matter.

To learn more about atoms, refer to the link:

https://brainly.com/question/1566330

#SPJ5

Answer: Solution D has the highest concentration of all.

Explanation:

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)

Molarity of permanganate solution = 0.1 M

Volume of solution = [tex]100 cm^3=100mL[/tex]        (Conversion factor: [tex]1mL=1cm^3[/tex])

Putting values in equation 1, we get:

[tex]0.1=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.1}{1000}=0.01mol[/tex]

Molarity of permanganate solution = 0.01 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]0.01=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 0.01}{1000}=0.001mol[/tex]

Molarity of permanganate solution = 2 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2}{1000}=0.2mol[/tex]

Molarity of permanganate solution = 2.5 M

Volume of solution = [tex]100 cm^3=100mL[/tex]

Putting values in equation 1, we get:

[tex]2.5=\frac{\text{Moles of permanganate solution}\times 1000}{100}\\\\\text{Moles of permanganate solution}=\frac{100\times 2.5}{1000}=0.25mol[/tex]

The solution having the highest number of moles will have the highest concentration for the same volume.

Thus, solution D has the highest concentration of all.

Answer:

Metals , silver and copper which allows to pass the electricity through it is called good conductor of electricity .

hope it is helpful to you ☺️

Answer:

Density of the solid=[tex]2.78 g/cm^3[/tex]

Explanation:

We are given that

Mass of sample of metal=4.369 g

Volume in the flask, V=126.4 ml

Mass of water, flask, and metal=268.5 g

Mass of flask=139.3 g

Density of water=1.000 g/mL

We have to find the density of the solid.

Mass of water=268.5-4.369-139.3=124.831 g

Volume of water=[tex]\frac{Mass\;of\;water}{density\;of\;water}[/tex]

Volume of water=[tex]\frac{124.831}{1}=124.831 mL[/tex]

Volume of solid=126.4 ml-124.831 mL

=1.569mL

Now,

Density of the solid=[tex]\frac{mass\;of\;solid}{volume\;of\;solid}[/tex]

=[tex]\frac{4.369}{1.569}[/tex]

[tex]=2.78g/mL[/tex]

1mL=1 cubic cm

Therefore,

Density of the solid=[tex]2.78 g/cm^3[/tex]

Answer: Decomposition is the answer

Explanation: why because aluminium hydroxide would decomposes in the presence of heat and would form an oxide which is aluminium oxide and would also form water as a product.

HOPE THIS HELPS!!

2H2O+O2--->2H2O2  

8.5 gm H2O2=0.25 mole  

hence H2O is also 0.25 mole i.e.4.5 gm  

O2is 0.125 mole i.e.4 gm

Answer:

(6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Explanation:

Question; From the given options, the chemical reaction in the question is presented as follows;

C₆H₁₂O₆(s) + 6O₂(g) → 6CO₂(g) + 6H₂O(l), given that we have;

[tex]\Delta \text H _f^{\circ}[/tex] for C₆H₁₂O₆ = -1,273.02 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for O₂(g) = 0 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for CO₂(g) = -393.5 kJ/mol

[tex]\Delta \text H _f^{\circ}[/tex] for H₂O(l) = -285.83 kJ/mol

The heat or enthalpy of a reaction,  is given as follows;

[tex]\Delta\text H_{rxn}^{\circ} = \sum \text n \cdot \Delta \text H _f^{\circ}(\text {products}) - \sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex]

Therefore, the equation which should be used to calculate [tex]\Delta\text H_{rxn}^{\circ}[/tex], is given as follows;

[tex]\sum \text n \cdot \Delta \text H _f^{\circ}(\text {products})[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol)

[tex]\sum \text m \cdot \Delta \text H _f^{\circ}(\text {reactants} \text)[/tex] = (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Therefore;

[tex]\Delta\text H_{rxn}^{\circ}[/tex] = (6 mol)·(-393.5 kJ/mol) + (6 mol)·(-285.83 kJ/mol) - (1 mol)·(-1,273.02 kJ/mol) + (6 mol)·(0 kJ/mol)

Answer:

sorry i dint understand can u ask it in a simpler way

Explanation:

Answer:

See explanation

Explanation:

In Bohr's theory, electrons are found in specific regions in space called orbits. These orbits are also called energy levels. An electron may move from one energy level to another by absorbing or emitting energy.

In the wave mechanical model, electrons are not found in a particular region in space according to Heisenberg's uncertainty principle.

We rather define a certain region in space where there is a high probability of locating the electron. This region in space where there is a high probability of locating the electron is called an orbital.

Hence, in the Bohr's model of the atom,electrons can surely be found in orbits while in the wave mechanical model, the orbital is a probability function that describes a region in space where an electron may be found.

Answer:

[tex]10 {7}^{2} = [/tex]

Answer:

Inference

Explanation:

I mean, it's not difficult.

A theory is an unproven explanation.

An inference is a guess/educated guess where you don't have all the facts.

For example, if "Bob" is caught in the kitchen with a ketchup stain on his shirt, you are inferencing that he used the ketchup.

However, if you see a ketchup bottle nearby or saw it earlier, then it is not, because you already have the facts that ketchup was used.

Answer:

1. How do metals and non-metals react with acids?

Ans : Non metals does not react with acids while metals react with acids and produce hydrogen gas that burns with a 'pop'sound.

2. Write and explain the chemical equation for the reaction of magnesium with sulphuric acid and aluminium with hydrochloric acid.

Magnesium + sulphuric acid = Hydrogen + salt

Mg(s) + H2SO4 (aq) MgSO 4(aq) +H2 (g)

Aluminium + Hydrochloric acid = Hydrogen + Aluminium chloride

2Al(s)+6HCl(aq)→2AlCl3(aq)+3H2(g)

Answer:

Metals react with acid but non metals donot react with acid because

when a substance, reacts with acids it provides electrons to the H+ ions produced by the acids. Non-metals are acceptors of electrons and hence, they cannot donate electrons.

Explanation: H2SO4 + Mg(OH)2 = H2O + MgSO4. 2Al+6HCl→2AlCl3+3H2 2 A l + 6 H C l → 2 A l C l 3 + 3 H 2

Answer:

25.6g de HF son producidos

Explanation:

...¿Cuánto HF es producido?

Para resolver este problema debemos convertir la masa de cada reactivo a moles usando su masa molar. Como la reacción es 1:1, el reactivo con menor número de moles es el reactivo limitante. Con las moles del reactivo limitante podemos obtener las moles de HF y su masa así:

Moles CaF2:

Masa molar:

1Ca = 40g/mol

2F = 19*2 = 38g/mol

40+38 = 78g/mol

50g CaF2 * (1mol/78g) = 0.641 moles CaF2

Moles H2SO4:

Masa molar:

2H = 2g/mol

1S = 32g/mol

4O = 64g/mol

98g/mol

100g H2SO4 * (1mol / 98g) = 1.02 moles H2SO4

Como las moles de CaF2 < Moles H2SO4: CaF2 es reactivo limitante.

Moles HF usando la reacción:

0.641 moles CaF2 * (2mol HF / 1mol CaF2) = 1.282 moles HF

Masa HF:

Masa molar:

1g/mol + 19g/mol = 20g/mol

1.282 moles HF * (20g/mol) =

Answer:

65.2%

Explanation:

It is given that :

[tex]$2NO + O_2 \rightarrow 2NO_2$[/tex]

Therefore, 60 g of nitrogen oxide will produce 92 g of nitrogen dioxide

or 60 kg of nitrogen oxide will produce 92 kg of nitrogen dioxide

or 1500 kg of nitrogen oxide will produce [tex]2300\ kg[/tex] of nitrogen dioxide

Therefore the percentage yield = (Actual yield / Expected yield) x 100

percentage yield = [tex]$\frac{1500}{2300} \times 100$[/tex]

Percentage yield = 65.217 %

Answer:

the person above me is correct, the answer for this is 65.2% or option D!

Explanation:

thank you person above me! i got a 100% on the test! :D

Answer:

Chemistry plays an important and useful role towards the development and growth of a number of industries. This includes industries like glass, cement, paper, textile, leather, dye etc. We also see huge applications of chemistry in industries like paints, pigments, petroleum, sugar, plastics, Pharmaceuticals.

[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

Hope it helps uh ✌️✌️✌️