The answer to this question is D as it says in the answer sheet of the question paper but how?

Answer:

Answer is A... Melting and freezing

Answer:

protons because they have the most positive charge

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:

See explanation

Explanation:

Let the equation of dissolution be;

AB2(s) ⇄A(aq) + 2S

Hence;

Ksp = [A] [2s]^2

Let the concentration of the species be s

Ksp= s × (2s)^2

Ksp= 4s^3

Since s= 5mol/dm^3

Ksp = 4(5mol/dm^3)^3

Ksp = 500 mol^2dm^-6

Answer:

2

Explanation:

Answer: The volume of the solution is 85.7 mL

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{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(1)

We are given:

Molarity of solution = 0.600 M

Given mass of [tex]BaSO_4[/tex] = 12.00 g

We know, molar mass of [tex]BaSO_4=[(1\times 137.33)+(1\times 32.07)+(4\times 16)]=233.4g/mol[/tex]

Putting values in equation 1, we get:

[tex]0.600=\frac{12.00\times 1000}{233.4\times \text{Volume of solution}}\\\\\text{Volume of solution}=\frac{12.00\times 1000}{233.4\times 0.600}=85.68mL=85.7mL[/tex]

The rule of significant number that is applied for the problems having multiplication and division:

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

Here, the least number of significant figures is 3 that is determined by the number, 0.600. Thus, the answer must have these many significant figures only.

Hence, the volume of the solution is 85.7 mL

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.

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:

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

Answer:

Give an example of each of the following chemical changes.

(a) A photochemical reaction involving

(i) silver salt

(ii) water

(b) A reaction involving

(i) blue solution

(ii) formation of dirty green precipitate

(c) Two gases combine to form white solid.

(d) A reaction where colour change is noticed.​

Explanation:

a) A photochemical reaction involving  silver salt is used in black and white photography.

AgCl breaks down and converts into Ag during this photochemical reaction.

(ii) Photochemicalreaction involving water takes place in plants during the photosynthesis process.

Plants prepare food(carbohydrate) by using sunlight water and CO2 gas.

(b) A reaction involving

(i) blue solution:

For example reaction of copper sulfate solution with an iron nail.

When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.

(ii) Reaction of ferrous sulfate with NaOH forms a dirty green precipitate of ferrous hydroxide.

(C) Two gases combine and form a white solid:

For example when HCl gas reacts with ammonia gas, then a white solid of ammonium chloride will be formed.

(d)  A reaction where the color change is noticed.:

When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.

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:

He should use a bar graph

Explanation:

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

Answer:

b temperature

Explanation:

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

Answer:

Hydroxyl

Explanation:

A P E X

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 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

Answer: Because this does not dissolve in water - it forms a barrier on the surface of the unreacted CaCO3 which prevents any further reaction. A small volume of CO2 is produced , but this stops after a short time . Conclusion: H2SO4 cannot be used with CaCO3 to produce CO2 gas .

Explanation:

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

#SPJ6

Answer:

This question is incomplete, the gravitational potential energy is 2.65 x 10^5 J

mass of the boulder = 866.7g

Explanation:

Potential energy (P.E) refers to the energy due to the position of a body. It can be calculated as follows:

P.E = m × g × h

Where;

m = mass of substance (g)

g = acceleration due to gravity (m/s²)

h = height (m)

According to the information provided in this question,

h = 31.2 m

g = 9.8m/s²

m = ?

P.E = 2.65 x 10^5 J

Using P.E = m × g × h

2.65 x 10^5 = m × 9.8 × 31.2

2.65 x 10^5 = 305.76m

265000 = 305.76m

m = 265000 ÷ 305.76

m = 866.69

mass of the boulder = 866.7g

Answer:

[tex]{ \tt{let \: the \: oxidation \: state \: be \: x}} \\ { \bf{x + sulphate \: ion+ water = overall \: charge}} \\ \\ \\ { \tt{x + ( - 2) + 0 = 0}} \\ \\ { \tt{x = + 2}} \\ { \tt{oxidation \: state = + 2}}[/tex]

D. 8

Hope this helps! :)

______________

Answer:

D: 8 neutrons would make it most stable

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]

1. and C.

Terrycot is a fiber that is made by mixing two fibers. Terrycot is a blended fabric made of terylene and cotton. It has better absorbing power as compared to Terylene. Nylon and terylene are produced through condensation polymeriztation.

Hope it helps...

Answer:

Explanation:

1-B

2-A

3-D

4-C

Answer:

???what metal????????????

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:

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.