Can anyone plz explain me this

Answer:

42,07%and 18,90%

Explanation:

Answer:

2

Explanation:

D. 8

Hope this helps! :)

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Answer:

D: 8 neutrons would make it most stable

83.3% yield

Explanation:

First, we need to convert 240 g of [tex]Fe_{2}O_{3}[/tex] into moles:

[tex]240 \:g \:Fe_{2}O_{3} \:\times(\frac{1\:\text{mol}\:Fe_{2}O_{3}}{159.69\: \text {g}\:Fe_{2}O_{3}})[/tex]

[tex]=1.50 \:\text{mol}\:Fe_{2}O_{3}[/tex]

Next, find the theoretical Fe yield using molar ratios.

[tex]1.50 \: \text {mol} \: Fe_{2}O_{3}\: \times (\frac{2\: \text{mol} \: Fe}{1 \:\text{mol} \: Fe_{2}O_{3}})[/tex]

[tex] = 3.00 \: \text{mol} \: Fe[/tex]

Then convert this back into grams:

[tex]3.00 \: \text{mol} \:Fe \times (\frac{55.845 \: \text{g} \: Fe}{1 \: \text{mol} \: Fe}) = 168 \: \text{g} \: Fe[/tex]

Note that actual yield is only 140 g Fe so percentage yield is

[tex]\dfrac{140\:\text{g}\:Fe}{168\:\text{g}\:Fe} \times 100[/tex]%= 83.3%

83.3%

The answer is 83.3%

Answer:

b temperature

Explanation:

Temperature is a measure of the average kinetic energy of the particles in a substance

Answer:

Thompson's experiments with cathode ray tube showed that every atom contains a small amount of negatively charged subatomic particles. Thomson proposed the plum pudding model of the atom.

Explanation:

Answer:

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

Explanation:

For problems like this posting, one needs an understanding of the following topics:

The definition of the mole

1 mole of substance = mass in grams of substance containing 1 Avogadro's Number ( = 6.023 x 10²³ ) of particles of the specified substance. This is generally one formula weight of the substance of interest. From this, the following equivalent relationships should be memorized:

  1 mole = 1 formula weight = 1 mole weight (g)= 6.023 x 10²³ particles

Converting grams to moles:

Given grams => moles = grams/gram formula wt

Converting moles to grams:

Given moles => grams = moles x gram formula wt

_________________________________________________________

Calculate the number of O atoms in 0.364 g of CaSO₄ · 2H₂O.

Given mass CaSO₄ · 2H₂O = 0.364 grams

Formula Wt CaSO₄ · 2H₂O = 172 g/mole

moles CaSO₄ · 2H₂O = mass CaSO4 · 2H2O / formula Wt. CaSO₄ · 2H₂O

= 0.364 g CaSO₄·2H₂O / 172 g CaSO4·2H2O

= (0.364/172) mole CaSO₄·2H₂O

= 2.12 x 10⁻³ mole CaSO₄·2H₂O    

∴ number of Oxy (O) atoms in 0.364 grams CaSO₄·2H₂O

=  (2.12 x 10⁻³ mole CaSO₄ · 2H₂O)(6.023 x 10²³ molecules CaSO₄· 2H₂O/ mole)

= 1.276876 x 10²¹molecules CaSO₄· 2H₂O  CaSO₄2H₂O

= 1.276876 x 10²¹ molecules CaSO₄· 2H₂O   x   6 oxygen atoms / molecule

= 7.661256 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

= 7.66 x 10²¹  oxygen atoms in 0.364 grams of  CaSO₄·2H₂O

Answer:

He should use a bar graph

Explanation:

Since this is a distinction between three very distinct categories a bar graph should be perfect

Answer:

26.85 grams

Explanation:

The formula for mole calculations is number of moles = given mass/gram-formula mass.

The number of moles is given to us, which is 0.125.

The gram formula mass of SnSO4 is about 214.77.

Plug in the values we have into the equation. It should look like this:

0.125 = x / 214.77

Solve for x by multiplying 214.77 and 0.125. The answer should be about 26.85 grams.

Answer:

it holds reactant molecules in a good position for then to react

Answer:

D. It holds reactant molecules in a good position for them to react.

Explanation:

Got a 100 on e2020.

Answer: The correct option is A) They have fixed energy values.

Explanation:

Electron is one of the sub-atomic particle present around the nucleus of an atom which is negatively charged.

In an atomic model, it is assumed that the electron revolves around the nucleus in discrete orbits having fixed energy levels.

These electrons when jumping from one energy level to another, some amount of radiation is either emitted or absorbed.

These fixed energy levels are given by the Bohr model and thus, the electrons are quantized.

Hence, the correct option is A) They have fixed energy values.

Answer: They have fixed energy values

Explanation: a pex

Explanation:

Dinitrogen monoxide: covalent bond

copper(||) hydroxide: ionic bond

Butane: Covalent Bond

Answer

Disulfur decafluoride S2F10 covalent

calcium sulfide  CaSO3 ionic

Diphosphorus tetraiodide P2I4 ionic

dinitrogen monoxide  N2O   ionic

Aluminum chloride  AlCl3  covalent

copper(II) hydroxide  Cu(OH)2  ionic

barium sulfate BaSO4  covalent

butane  C4H10  covalent

Explanation:

edmentum

Answer:

Tetrahedral. Tetra- signifies four, and -hedral relates to a face of a solid; “tetrahedral” literally means “having four faces. ” This shape is found when there are four bonds all on one central atom, with no lone electron pairs. In accordance with the VSEPR theory, the bond angles between the electron bonds are 109.5o ...

There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the geometry of given molecule is tetrahedral.

VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.

According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element.

A molecule has four bonded atoms around a central atom. The central atom does not have any lone pairs of electrons. The geometry of such molecule is Tetrahedral. Geometry does not include lone pair on central atom.

Therefore, the geometry of given molecule is tetrahedral.

To know more about VSEPR theory, here:

https://brainly.com/question/19582124

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Answer:

when d volume of a substance is high, the concentration is gonna b low...

Jus lyk putting much water in just a cube of sugar

Explanation:

So lower volume, higher concentration

Answer: The oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.

Explanation:

Given: [tex]V_{1}[/tex] = 2 L,        [tex]P_{1}[/tex] = 2 atm

[tex]V_{2}[/tex] = 1 L,          [tex]P_{2}[/tex] = ?

Formula used to calculate the new pressure is as follows.

[tex]P_{1}V_{1} = P_{2}V_{2}[/tex]

Substitute the values into above formula as follows.

[tex]P_{1}V_{1} = P_{2}V_{2}\\2 atm \times 2 L = P_{2} \times 1 L\\P_{2} = 4 atm[/tex]

Thus, we can conclude that the oxygen gas has a pressure of 4 atm if my volume decreases to 1 L.

Answer: The number of moles of gas which are present in the sample are 1.49 mol.

Explanation:

Given: Volume = 55.3 L

Temperature = [tex]23.3^{o}C[/tex] = (23.3 + 273) K = 296.3 K

Pressure = 0.658 atm

Formula used is as follows.

PV = nRT

where,

P = pressure

V = volume

n = no. of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]PV = nRT\\0.658 atm \times 55.3 L = n \times 0.0821 L atm/mol K \times 296.3 K\\n = \frac{0.658 atm \times 55.3 L}{0.0821 L atm/mol K \times 296.3 K}\\= \frac{36.3874}{24.32623}\\= 1.49 mol[/tex]

Thus, we can conclude that the number of moles of gas which are present in the sample are 1.49 mol.

Answer:

A helium nucleus

Thre types of radiation

Alpha: Helium nucleus

Beta: Electron

Gamma: Gamma rays

Answer:

16.7 %(m/m)

Explanation:

The percent by mass of a solution (% m/m) is defined as 100 times the ratio of the mass of solute (The substance in the lower amount, NaCl) and the mass of the solution = Mass solute + Mass Solvent (water).

Mass Solution:

100g NaCl + 500g water = 600g solution

Mass Percent:

100g NaCl / 600g solution * 100

= 16.7 %(m/m)

Complete Question

4. A piece of metal weighing 0.0713 g was placed in a eudiometer containing dilute aqueous HCl. After the metal fully dissolved, 23.5 mL of hydrogen gas was collected by displace-ment of water and a 400 mm column of water was observed. The water temperature was 258C and the barometric pressure was 758.8 mm Hg (torr). Refer to the Introduction and data sheet to solve the following problems.

a) What is the vapor pressure of the water vapor in the column? (Consult Appendix E.)

b) What is the pressure of the water column expressed in mm Hg (torr)? The density of mercury is 13.6 g/mL.

c) Calculate the pressure of the hydrogen gas above the water in the column.

d) Calculate the volume occupied by the hydrogen gas at STP.

Answer:

a)  [tex]25\textdegree C=23.8 torrs[/tex]

b) [tex]P_w=758.8[/tex]

c)  [tex]P_w=758.8=735torr[/tex]

d)  [tex]V_2=20.82mL[/tex]

Explanation:

From the question we are told that:

Metal weight [tex]M_m=0.0713g[/tex]

Volume Hydrogen [tex]V_h=23.5mL[/tex]

Displace-ment Column of water 400 mm column of water

Temperature [tex]T =258\textdegree C[/tex]

Barometric Pressure [tex]p=758.8mmHg[/tex]

Vapour Pressure of water at [tex]25^oC[/tex]

Generally from (Consult Appendix E.)

a)

Va-pour Pressure of water at

[tex]25\textdegree C=23.8 torrs[/tex]

b)

Pressure of Water column

[tex]P_w=758.8[/tex]

c) Pressure of Water column (Consult Appendix E.)

[tex]P_w=758.8=735torr[/tex]

d)

Generally the equation for ideal gas is mathematically given by

 [tex]\frac{p_1v_1}{T_1}=\frac{p_2v_2}{T_2}[/tex]

Therefore

 [tex]V_2=\frac{p_1V_1T_2}{T_1p_2}[/tex]

 [tex]V_2=\frac{735*23.5*273}{298*760}[/tex]

 [tex]V_2=20.82mL[/tex]

Answer:

The entropy and the systems surrounding it tend to increase.

Answer: The entropy in a system and its surroundings tends to increase.

Explanation:

3.3.2 Quiz: Entropy (a p e x)

Answer:

See explanation

Explanation:

Let us recall that the basic rule in writing balanced chemical reaction equations is that the number of atoms of each element on the right hand side of the reaction equation is the same of the number of atoms of the same element on the left hand side of the reaction equation.

The reaction of red hot iron and steam is written as follows;

3Fe + 4H2O → Fe3O4 + 4H2.

The decomposition reaction of ammonium dichromate is written as;

(NH4)2Cr2O7 → N2 + Cr2O3 + 4H2O

Reaction of aluminium, sodium hydroxide and water is as follows,

2Al + 2NaOH + 2H2O ----> 2NaAlO2 + 3H2

Reaction of potassium bicarbonate with sulphuric acid;

2KHCO3 + H2SO4 -------> K2SO4 + 2H2O + 2CO2

Reaction of zinc and sodium hydroxide is as follows;

Zn + 2NaOH→Na2ZnO2 + H2

Answer:

A

Explanation:

did that on my test

Answer:

It's take 1 and a half hours

Explanation:

Ugbdunvisrtg

Answer:

Organic molecules are important to living things because life is based on the properties of carbon.

Properties of Carbon

Carbon is an important element because it can form four covalent bonds.

Carbon skeletons can vary in length, branching, and ring structure.

The carbon skeletons contain the functional groups that are involved in biochemical

Explanation:

Hope it helps