What was John Dalton's contribution to the development of the atomic theory?

Answers

Answer 1

John Dalton made some hypothesis about the structure of atom. He proposed that matter is composed of great number of indivisible particles called atoms they can neither be destroyed nor be created.

What is atomic theory?

There are different theories regarding the structure and electronic properties of an atom. Many scientists contributed to the modern theory of atomic structure in which John Dalton was first to mention the word atom.

According to Dalton' theory, matter is composed of indivisible particles called atoms. Atoms can neither be created nor be destroyed. All the atoms of the same element are identical in all aspects.

Atoms of different elements are different and the compounds are formed by the combination of atoms.  Dalton's theory provided a sound basis for the laws of chemical combination and also several properties of gases and liquids known at that time.

However, he could not explain the reason for chemical combination of atoms and did not give any idea about the existence of isotopes and isobars.

Hence, the main aspects of Dalton's theory was the indivisibility of atoms and the chances of chemical combination.

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Related Questions

URGENT!!!!

Part D: Challenge
An unknown mixture is set in beaker on the teacher's table. Describe the five different parts of the
mixture and how we can separate it.

Answers

An unknown mixture is set in beaker on the teacher's table the five different parts of the mixture and we can separate it by method evaporation, distillation, sedimentation, and filtration

Mixture is the composed of one or more pure substances in varying compositions called as mixture and unknown mixture is separated by  shake the separatory funnel to allow intimate mixing of the solutions and effect extraction of the compound from the organic mixture and mixture can be physically separated by sedimentation process, filtration, crystallization, distillation, diffusion, panning, magnetic separation, and adsorption are a few of the methods used to separate materials and the substance is said to be pure when a sample of it has purified all other type of material

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What formed a channel on mars?

Answers

Continental drift is a geologic process that forms channel on Mars.

Continental drift, the same process that creates contemporary channels like the mid-Atlantic channel or the African Rift Valley, is the geologic process that is most likely to have created the channel on Mars. Massive troughs that are visible from orbit are being exposed when Mars' tectonic plates separate. Similar to Earth, Mars too experiences gradual continental drift, which moves by less than an inch per year and is much too slow for any person to notice. However, this can lead to significant geological and geographic changes over millions of years that modify the planet's surface.

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1. What type of TV uses a CCFL for backlighting?
O 3D
O LCD
OLED
O Cathode Ray tube

Answers

Explanation:

When a virus infects a bacterial cell, often new viruses are assembled and released when the host bacterial cell is lysed. If these new viruses go on to infect new bacterial cells, the new host cells may not be lysed. What is the most plausible explanation for this?A) The bacterial cell must be resistant to infection by the virus.

B) The virus carries genes that confer resistance to the host bacterial cell.

C) The host bacterium couples the viral infection with transformation.

D) The virus has entered the genome of the bacterial cell and is in the lysogenic stage.When a virus infects a bacterial cell, often new viruses are assembled and released when the host bacterial cell is lysed. If these new viruses go on to infect new bacterial cells, the new host cells may not be lysed. What is the most plausible explanation for this?A) The bacterial cell must be resistant to infection by the virus.

B) The virus carries genes that confer resistance to the host bacterial cell.

C) The host bacterium couples the viral infection with transformation.

D) The virus has entered the genome of the bacterial cell and is in the lysogenic stage.

Answer:

LCD TV's use a CCFL for backlighting

Consider the following generic reaction: A+2B→C+3D, with ΔH = 157 kJ . Determine the value of ΔH for C+3D→A+2B.

Answers

Taking into account the definition of enthalpy of a chemical reaction,  the value of ΔH for C + 3D → A + 2B is -157 kJ.

Definition of enthalpy of a chemical reaction

The enthalpy of a chemical reaction as the heat absorbed or released in a chemical reaction when it occurs at constant pressure. That is, the heat of reaction is the energy that is released or absorbed when chemicals are transformed into a chemical reaction.

A negative value of an enthalpy change indicates an exothermic reaction; a positive value of ΔH indicates an endothermic reaction.

Reversing the direction of a chemical equation changes the arithmetic sign of ΔH because a process that is endothermic in one direction is exothermic in the opposite direction.

Value of ΔH in this case

In this case, the balanced reaction is:

A + 2B → C + 3D

and the enthalpy reaction ∆H° has a value of 157 kJ and it is an endothermic reaction.

To calculate the value of ΔH for C + 3D → A + 2B, you can see that the reaction is inverted, being in this case an exothermic reaction. Then, the enthalpy value must be reversed from sign.

Finally, the value of ΔH is -157 kJ.

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If soil erosion is happening at a greater rate than new soil can form, what will eventually happen to the soil in that region? Find a real-life example of this by googling "areas of extreme soil degradation."

Answers

Likely the foremost recognizable impact of soil disintegration is land degradation.

Asia-Pacific region is an area of extreme soil degradation.

Likely the foremost recognizable impact of soil disintegration is land debasement. As disintegration wears down the soil and its arrival, its capacity to bolster plant life diminishes.

Around the globe, soil disintegration is happening at a speedier rate than it can regenerate. When arrival corrupts, it annihilates territories and diminishes the sum of arrival accessible for agricultural needs or the requirements of natural life.

Since of land degradation, the soil cannot back plant life. Plants require solid, nutrient-filled soil to develop and deliver. In case the ground isn’t able to back vegetation, you won’t be able to develop nourishment.

Other than that, with fewer plants accessible to sequester carbon dioxide from the environment, the rate of climate alters increments. Increasingly carbon dioxide is cleared out within the climate, which is causing harm to the environment.

It increments the earth’s normal temperature and modifies precipitation, both of which can advance the progress of desertification.

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calculate the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C

Answers

Answer:0.74

Explanation:0.74

14.67KJ is the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C.

What is heat?

The vibrations of molecules or atoms increase when a body's temperature rises. From one area of the body to another, these vibrations are then transmitted. The amount of energy that a system's molecules vibrate with is referred to as its stored heat.

According to the definition of heat, it is the movement of energy from a warm item to a cooler one. The flow of heat energy is in the direction of moving from a substance with a higher temperature to one with a lower temperature.

q =mcΔT

    =32.0×4.18×(110-40)

    = 14.67KJ

Therefore, 14.67KJ is the number of joules given off when 32.0 grams of steam cools from 110.0 C to ice at -40.0 C.

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some ammonia is sealed in a container and allowed to equilibrate at a particular temperature. the reaction is endothermic. 2nh3(g) ↔ n2(g) 3h2(g) in which direction will the reaction occur if ammonia is added to the system?

Answers

If ammonia is added to the system, the reaction will shift to the right, in favour of the forward direction.

A reaction is said to be at equilibrium when the concentration of reactants is equal to the concentration of the products. This means that the rate at which reactants are forming products is equal to the rate at which products are changed back to reactants.

All reactions at equilibrium follow Le Chatelier's principle, which states that if a chemical system in equilibrium is disturbed by changing the conditions (such as concentration, temperature and pressure changes), the position of equilibrium shifts to the left or to the right in order to counteract the change and to re-establish an equilibrium.

This means that if certain factors in a chemical reaction at equilibrium is changed, the reaction will shift either to the left or to the right. If it shifts to the left, the backward reaction is favoured and more reactants are produces, but if it shifts to the right, the forward reaction is favoured, and more products are produced.

In the question above, ammonia (2NH₃) is added to the chemical system. This will cause an increase in the concentration of ammonia; hence, more ammonia will be converted to nitrogen and hydrogen in order to decrease the concentration of ammonia and re-establish equilibrium. This causes the reaction to shift to the right.

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HELP PLS ASAP
Ben is at the beach by the sea with his parents. After swimming, he dried off in the sun and discovered small, salty tasting white crystals on his skin. Explain what happened.

Answers

Answer:

what happened was when he dried off, there was still a little salt water on him. so, since the water has salt in it and the sun is very hot wich makes salty dried up as hard salt on him.

what is the proper method to determine the mass number of an isotope

Answers

Answer:

Subtract the atomic number (the number of protons) from the rounded atomic weight. This gives you the number of neutrons in the most common isotope. Use the interactive periodic table at The Berkeley Laboratory Isotopes Project to find what other isotopes of that element exist.

Explanation:

Forms of the same atom that differ only in their number of neutrons are called isotopes. Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons.

if 1.00 x 1018 singly charged positive sodium ions flow from the anode of an electrochemical cell each second and an equal number of singly charged negative chlorine ions flow from the cathode of the cell, how much current flows through the cell?

Answers

Total current flows through the cell I = 0.32 Amp

What is electrochemical cell?

An electrochemical cell is a device that either generates energy from chemical reactions inside of it or uses electricity to power various chemical processes inside of it.

Given,

Sodium ion flows from anode and negatively charged ion flowing from cathode

so if you write the equation that will be

Na - e ⇄ Na⁺

Cl⁻ + e ⇄  Cl

Now current flowing is the number of charges flowing per unit second

here total current is due to cation (Na⁺) and anion (Cl)

so only one electron is associated here,

so total current (I) = 10¹⁸ ˣ 1.6 ˣ 10⁻¹⁹ Amp.  

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9. given that methane (aka. natural gas, ch4) has a fuel value of 55.5 mj/kg and hydrogen (h2) has a fuel value of 142 mj/kg, compare and contrast these fuels with the best combination determined by the class.

Answers

From the comparison of methane and hydrogen gases, it is found that Hydrogen gas, H₂ will be the best fuel

From the given question, we have:

CH4 and H₂ have fuel values as following;

For CH4=55.5mj/kg

For H[tex]_{2}[/tex]=142mj/kg

When we combust CH4 It will produce CO[tex]_{2}[/tex] gas and water as a product. The CO[tex]_{2}[/tex] gas is an environment pollutant and it also has low fuel value

However, if we combust H₂, It will produce only H₂O, which is environmentally healthy and also produces more fuel value.

Hence, H₂ will be the best fuel

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2. Which metal reacted most vigorously when placed in the acid? Give evidence to
support your answer.

Answers

Answer:

The alkali metals (Li, Na, K, Rb, Cs, and Fr) are the most reactive metals in the periodic table – they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.

Explanation:

The metal that reacted most vigorously when placed in the acid is sodium, as it is an alkali metal.

What are alkali metals?

At standard temperature and pressure, all of the bright, soft, extremely reactive alkali metals rapidly shed their outermost electron to create cations with charge +1.

One of the most reactive metals is the alkali metal. They have greater atomic radii and low ionization energies, which contribute to this. They have an oxidation state of 1, and they frequently give electrons during reactions. These metals stand out for their supple texture and silvery hue.

The alkali metals (Li, Na, K, Rb, Cs, and Fr) are the most reactive metals in the periodic table – they all react vigorously or even explosively with cold water, resulting in the displacement of hydrogen.

Therefore, the correct option is d. sodium.

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The question is incomplete. Your most probably complete question is given below:

Oxygen

magnesium

iron

sodium

a solution containing 3.76 g naoh in 361 ml water is titrated to the endpoint with 491 ml hcl. what is the molar concentration of hcl in the original solution? a. 0.13 b. 130 c. 0.0031 d. 0.00053 e. 0.19

Answers

The molar concentration of HCl in the original solution is 0.19

The balanced chemical equation for the reaction must be our starting point because it will provide us with the reactants' mole ratios and allow us to answer this question.

* NaOH + HCl --> NaCl + H2O

this means:

1 mole NaOH reacts with 1 mole HCl

thus the ratio of NaOH to HCl is 1: 1

Next we've got to calculate the moles of NaOH: (molecular Mass = 40 g/mol)

moles(NaOH) = 3.76g/40

= 0.094 moles

Now we can calculate the concentration of NaOH:

Note: 361mL/1000 = 0.361L

conc(NaOH) = 0.094 moles/0.361L

= 0.26 mol/L

Now the mole ratio of NaOH to HCl is 1:1

But we have used only 0.094 moles so since the ratio of NaOH to HCl is 1:1, it means that 0.094moles of NaOH can only react with 0.094 moles of HCl.

Note: 491mL/1000mL = 0.491L

conc(HCl) = 0.094 moles/0.491L

= 0.19 mol/L

Thus the molar concentration of HCl in the original solution is 0.19

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the lead-acid storage battery is the oldest rechargeable battery in existence. it was invented in by french physician gaston plante and still retains application today, more than years later. there are two reactions that take place during discharge of the lead-acid storage battery. in one step, sulfuric acid decomposes to form sulfur trioxide and water: (l) (g) (l) in another step, lead, lead(iv) oxide, and sulfur trioxide react to form lead(ii) sulfate: (s) (s) (g) (s) calculate the net change in enthalpy for the formation of one mole of lead(ii) sulfate from lead, lead(iv) oxide, and sulfuric acid from these reactions. round your answer to the nearest .

Answers

The net change in enthalpy for the formation of one mole of lead(ii) sulfate from lead, lead(iv) oxide, and sulfuric acid is -274.5 KJ,

Calculation

Reaction 1: [tex]H_{2} SO_{4(aq)}--- > SO_{3(g)} +H_{2} O_{(l)}[/tex] ,  Δ[tex]H^{Q} = +113 KJ[/tex]

Reaction 2: [tex]Pb_{(s)} +PbO_{2(s)} +2SO_{3(s)} --- > 2PbSO_{4(aq)}[/tex] Δ[tex]H^{Q} =-775 KJ[/tex]

To calculate the net change in enthalpy for the formation of 1 mole of [tex]PbSO_{4(aq)}[/tex]

Divide reaction 2 by  2

⇒[tex]\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +\frac{2SO_{3(s)}}{2} --- > \frac{2PbSO_{4(aq)}}{2}[/tex],  Δ[tex]H^{Q} =\frac{-775}{2} KJ[/tex]

⇒[tex]\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +SO_{3(s) --- > PbSO_{4(aq)[/tex] , Δ[tex]H^{Q} =-387.5 KJ[/tex]

Subtract reaction 1 with the above reaction

[tex]H_{2} SO_{4(aq)}--- > SO_{3(g)} +H_{2} O_{(l)}-\frac{Pb_{(s)}}{2} +\frac{PbO_{2(s)}}{2} +SO_{3(s) --- > PbSO_{4(aq)[/tex]

⇒[tex]H_{2} SO_{4(aq)}+\frac{Pb_{(s)}}{2}+\frac{PbO_{2(s)}}{2} --- > PbSO_{4(aq)}+H_{2} O_{(l)}[/tex]

Δ[tex]H^{Q}[/tex]=Δ[tex]H^{Q} Product[/tex]+Δ[tex]H^{Q} Rreactant= -387.5 KJ+113 KJ[/tex]

Δ[tex]H_{formation} =-274.5 KJ[/tex]

What is the enthalpy change?An enthalpy change is roughly equivalent to the energy gained through the production of new chemical bonds in a reaction minus the energy required to break existing chemical bonds. It describes how a system changes in terms of energy while pressure is constant. The symbol H stands for enthalpy change. At constant pressure, H is equal to the sum of the system's internal energy and the pressure-volume work it performs on its surroundings.

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can someone help me with balancing this chemical equation?
( ^ means subscript )
NH^3+0^2= NO+H^2O

Answers

This chemical equation is balanced.

What is chemical equation?

chemical equation are symbolic representation of chemical reactions in which the reactants and the product are expressed in term of their respective chemical formula.

Reactants are converted to products and the process is symbolise by a chemical equation.

Sol-

NH^3+O^2------>NO+H^2O

2NH^3+O^2----->2NO+3H^2O

2NH^3+O^2------>2NO+3H^2O

2NH^3+5/2 O^2------2NO+3H^2O

2NH^3+5/2 O^2------->2NO+3H^2O

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what volume in liters of fluorine gas is needed to form 639 l of sulfur hexafluoride gas if the following reaction takes place at 2.00 atm and 273.15 k: s(s) 3f₂(g) → sf₆ (g)?

Answers

For producing 639L of [tex]SF_6[/tex], a volume of 1916.96L of [tex]F_2[/tex] gas is required for the reaction.

If the pressure and temperature at which the reaction occurs is known, we may use the ideal gas law to compute the stoichiometry of processes involving gases by using the connection between the volume (in liters) and quantity of gases (in moles). A chemical reaction's volume of gas can be evaluated by collecting it in an inverted vessel filled with water. The gas pushes water out of the vessel, and the amount of liquid displaced is proportional to the amount or volume of gas.

Given:

Volume of [tex]SF_6[/tex] = 639L

Pressure, P = 2atm

Temperature, T = 273.15K

To find:

Volume, V of [tex]F_2[/tex] gas = ?

Formula:

PV = nRT

Calculations:

No. of moles of [tex]SF_6[/tex] = 2 x 639 / 0.082 x 273.15

No. of moles of [tex]SF_6[/tex] = 57.057 moles

[tex]S (s) + 3F_2 (g) \rightarrow SF_6 (g)[/tex]

From the reaction,

1 mole of [tex]SF_6[/tex] is formed from 3 moles of [tex]F_2[/tex]

Therefore,

No. of moles of [tex]F_2[/tex] = 3 x 57.057 = 171.171 moles

Volume of [tex]F_2[/tex] = 171.171 x 0.082 x 273.15 / 2

Volume of [tex]F_2[/tex] = 1916.96L

Result:

1916.96L of [tex]F_2[/tex] gas is required to produce 639L of [tex]SF_6[/tex].

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Question 9What pressure will be exerted by 15 g of carbon dioxide gas in a 20 L container at 0 °C?

Answers

In this question, we need to find the value of pressure of a 15 grams sample of CO2 gas, and in order to find this value, we will be using the Ideal gas law formula, which is the following:

PV = nRT

Where:

P = pressure in atm

V = volume in liters, 20 Liters

n = number of moles

R = gas constant, 0.082

T = temperature in kelvin, 0°C = 273 K

The number of moles we need to find based on the mass in the question and based on the molar mass of CO2, 44g/mol:

44g = 1 mol

15g = x moles

44x = 15

x = 15/44

x = 0.34 moles of CO2 in 15 grams

Now we have the values to add to the formula:

P * 20 = 0.34 * 0.082 * 273

20P = 7.61

P = 7.61/20

P = 0.38 atm of pressure

The pressure will be 0.38 atm

please help me on this question

Answers

Answer:

c

Explanation:

ch4 + 4cuo --> CO2 + 2h20 + 4cu

consider the reaction when aqueous solutions of ammonium phosphate and chromium(ii) sulfate are combined. the net ionic equation for this reaction is:

Answers

Explanation:

The reaction of aqueous solutions of iron(II) sulfate and ammonium phosphate leads to the formation of solid precipitate of iron phosphate and an aqueous solution of ammonium sulphate.

Molecular equation :

3

F

e

(

S

O

4

)

(

a

q

)

+

2

(

N

H

4

)

3

P

O

4

(

a

q

)

F

e

3

(

P

O

4

)

2

(

s

)

+

3

(

N

H

4

)

2

S

O

4

(

a

q

)

Total ionic equation :

3

F

e

+

2

(

a

)

+

3

(

S

O

4

)

2

(

a

q

)

+

6

(

N

H

4

)

+

(

a

q

)

+

2

P

O

3

4

(

a

q

)

F

e

3

(

P

O

4

)

2

(

s

)

+

6

(

N

H

4

)

+

(

a

q

)

+

3

S

O

2

4

(

a

q

)

Net ionic equation :

By canceling the spectator ions from total ionic equation, we get

3

F

e

+

2

(

a

q

)

+

2

P

O

3

4

(

a

q

)

F

e

3

(

P

O

4

)

2

(

s

)

when enzyme solutions are heated, there is a progressive loss of catalytic activity over time due to denaturation of the enzyme. a solution of the enzyme hexokinase incubated at 45 ∘c lost 50% of its activity in 12 min, but when incubated at 45 ∘c in the presence of a very large concentration of one o

Answers

Both the substrates as well the enzymes do not undergo denaturation since the enzyme was incubated with the substrate and it lost its activity.

When a certain substrate comes into contact with an enzyme, it will bind to the active region. Binding of the substrate to the active region of the protein results in the formation of a more stable enzyme substrate complex. This is because the enzyme substrate complex is more resistant to heat denaturation than just the enzyme.

Because the enzyme-substrate complex ground state has a lower energy level, more energy is required to overcome this energy barrier and denature the enzyme. In the question, it is given that 3% of the enzyme lost its activity, which might have happened when the enzyme and the substrate were incubated. Only 3% of the enzyme was liberated after the denaturation step, leaving 97% occupied with substrate.

As a result, neither the enzyme nor the substrate undergoes denaturation.

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An atom of Iodine contains 75 neutrons. What is its mass number?

Answers

Answer:

128

Explanation:

Iron has atomic number of 53

so mass number is 53 + 75 = 128

problem 2 (10 pts).2.00 gram-moles of dichloromethane are contained in a vessel at 100. °c and 12.0 atm. a. 5pt) what is the system volume (l) based on the ideal gas equation? b. 5pt) suppose the actual volume of the vessel is 4.50 liters. what percentage error results from assuming ideal-gas behavior?

Answers

The volume of the system is found to be 5.097L and the % error is found to be 13.2%.

Every three-dimensional item requires some amount of space. The volume of this space is measured. Volume is defined as the space occupied by an item inside the confines of three-dimensional space. It is also known as the object's capacity. Volumes change depending on the form.

The absolute value of the difference between the measured and actual values is divided by the actual value and multiplied by 100 is the % error. Percent mistakes indicate the magnitude of your errors while measuring anything in an experiment. Smaller numbers of % error indicate that you are getting nearer to the acceptable or true value.

Given:

P = 12atm

n = 2 moles

T = 100℃ = 100 + 273 = 373K

To find:

(a) V = ?

(b) % error = ?

Formula:

PV = nRT

% error = (experimental – actual) / actual x 100

Calculations:

(a) V = nRT/P

V = 2 x 0.082 x 373 / 12

V = 5.097L

(b) % error = (5.097 – 4.5) / 4.5 x 100

% error = 0.597 / 4.5 x 100

% error = 0.132 x 100

% error = 13.2%

Result:

The system’s volume is 5.097L and the % error is 13.2%.

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Alan and Faisyal are talking about why pieces of two different metals that are the same size have very different masses. Alan says that the particles must be different masses, and Faisyal says that it is to do with how the particles are arranged. Are they correct? What would you say to them?

Answers

Yes, Alan and Faisyal are both correct. Two metals or objects can have the same outward structure but different masses. This is because of the way their atoms or particles are arranged. The way in which the particles of matter are arranged is called Density.

What is the density of Matter?

The degree of compactness of a substance is measured by its density. It is the amount of mass per unit volume that determines the degree of uniformity. It is the connection between a substance's mass and the quantity of space it takes up.

The density of a material is its mass per unit volume. The most common sign for density is ρ, however, the Latin letter D can also be used. Density is defined mathematically as mass divided by volume.

The formula for density is given as ρ= m/V, where is the density, m is the object's mass, and V is the object's volume. The density of an item is defined as its mass per unit volume. The kilogram per cubic meter (kg/m3) is the SI unit of density.

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Hydrated sodium tetraborate is heated
to drive off the water. You find there are
0.01312 mol Na2B4O7 and 0.1311 mol
H2O in the sample. What is the formula
of the hydrate?
A. Na2B4O7 H₂O
B. Na2B4O7 2H₂O
C. Na2B4O7-10H₂O
D. Na2B4O7-13H₂O

Answers

Answer: C. Na2B4O7•10H2O

Explanation:


Hope this helps :)

The formula is tetrasodium borate-Na2B4O7.10H2O

Given- 0.0132 mol Na2B4O7 and 0.1311 mol H2O

Step 1

Using the molar mass of the anhydrous Na2B4O7 and its mass percentage, we can calculate the molar mass of the hydrate (if we look at it as 100% of the mass) by stoichiometry.

Molar mass of Na = (22.990 g/mol)

Molar mass of B = (10.811 g/mol)

Molar mass of O = (15.999 g/mol)

Molar mass of Na2B4O7= 2⋅22.990 g/mol +4⋅10.811 g/mol +7⋅15.999 g/mol = 201.217 g/mol

201.217g/mol : 52.8%=x g/mol : 100%

​x g/mol = 201.217 g/mol⋅100%÷52.8 %

x g/mol= 381.093 g/mol

Step 2

In 381.093 g of hydrate, we have 201.217 g of anhydrous Na2B4O7 , the rest of the mass is water.

381.093g−201.217g= 179.876 g of water

Molar mass of H = 1.008 g/mol

Molar mass of O = 15.999 g/mol

Molar mass of  H2O= 1.008 g/mol+ 15.999g/mol  = 18.015 g/mol

179.876g ÷18.015 = 9.98= 10 moles of water per mole of hydrate.

When metals bond with other elements to create new compounds, which type of element do they mainly react with?.

Answers

Chemical compounds are created when elements combine and are frequently separated into two groups. Ionic compounds are frequently created when metals and nonmetals react.

These substances are made of neutral atoms and molecules that have had their electrons added to or taken away to generate positive and negative ions.

The mantle and the solid inner core are separated by this layer of the planet. It is the sole liquid layer, a 1,400 mile sea made largely of iron and nickel. Iron and nickel make up the majority of the lava. The magnetic field of the Earth is produced by the outer core. The inner core, which is the last layer, is 900 miles deep. According to scientists, the inner core is a solid ball of minerals and iron.

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Which statement is correct in the process of balancing the equation?

Answers

The correct statement in the process of balancing the equation is option C which is Do nothing, the equation is already balanced.

The chemical equation which is given in the question is -

CH₄ + O₂ → CO₂ + 2 H₂O

This reaction is a balanced chemical reaction as number of atoms of product and reactant are equal.

Number of carbon atoms on reactant side is 1 and number of carbon atoms on product side is also 1. Number of oxygen atoms on product side is 2 and hydrogen atoms is 4 and on reactant side, number of oxygen atom was 1 and number of hydrogen atom was 2 but after adding coefficient 2 in front of H₂O, number of Oxygen atoms became 2 and number of hydrogen atom became 4 making it a balanced reaction.

Therefore, correct option for process of balancing the equation is C.

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In two to three sentences, explain the trend for atomic size. Why does this trend occur?

Answers

Answer:

Atomic Size Trend Across the Period

This is caused by the increase in the number of protons and electrons across a period. One proton has a greater effect than one electron cause of the coulombic law. Thus, electrons are pulled towards the nucleus, resulting in a smaller radius.

Explanation:

Which phase of matter is the least common on Earth?
A. Gases
B. Liquids
C. Solids
D. Plasma

Answers

Answer:

the answer is....... D. Plasma

Answer:

Plasma

Explanation:

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a person with cystic fibrosis typically contains 60-200 mm cl- in samples of their perspiration. the chloride in a 1.0 ml aliquot of such a sample is to be measured by combining it with 1.0 ml of a reagent containing 0.0250 m agno3. ksp

Answers

In the diagnosis of cystic fibrosis caused by gene mutation, the mass of AgCl formed and the mass of [tex]Cl^-[/tex] remaining are 0.003583g and 0.006203g respectively, and the % of [tex]Cl^-[/tex] precipitated is 12.5%.

Cystic fibrosis (CF) is a hereditary condition that causes respiratory and gastrointestinal issues. An alteration (mutation) in the gene that produces the cystic fibrosis transmembrane regulator (CFTR) protein causes cystic fibrosis. To be born with CF, a new born must get two copies of the CF gene, one from each parent.

Cystic fibrosis causes thick, sticky mucus to accumulate in the lungs. CF causes recurring lung infections and makes breathing difficult over time. Other organs of the body, like the pancreas, might be affected by Cystic fibrosis, making it difficult to digest meals and maintain a healthy weight.

a) Mass of AgCl precipitate = no. of moles x molecular mass

Mass = 0.025mol/L x 0.001L x 143.32g/mol

Mass = 0.003583g

b) Mass of [tex]Cl^-[/tex] remaining in solution after precipitation = no. of moles x molecular mass

No. of moles of [tex]Cl^-[/tex] = 0.2mol/L x 0.001L = 0.0002 mol

No. of moles of [tex]Ag^+[/tex] = 0.25mol/L x 0.001L = 0.000025 mol

Mass of [tex]Cl^-[/tex] remaining = (0.0002 – 0.000025) x 35.45

Mass of [tex]Cl^-[/tex] remaining = 0.006203g

c) % of [tex]Cl^-[/tex] precipitated = 0.000025 / 0.0002 x 100 = 12.5%

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The drawing below shows the effect of moving air on a desert sand dune.
Which most likely describes the event in the drawing?



The drawing below shows the effect of moving air on a desert sand dune.






Which most likely describes the event in the drawing?



It is an example of erosion by gravity.



It is an example of erosion by wind.



It is an example of physical weathering by wind.



It is an example of physical weathering by gravity.

Answers

The drawing below shows the effect of moving air on a desert sand dune describes the event in the drawing it is an example of erosion by wind

Natural sand dunes usually start as windblown sand that accumulates in a sheltered area behind some type of obstacle such as piles of seaweed and a hill of sand made up of wind on the coast or in a desert and it is because of erosion by wind strong winds blow across the loose sand on the surface of the earth including sands found in deserts and beaches that's why  erosion by wind most likely describes the event in the drawing

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