What is the oxidation number of phosphorus (P) in phosphoric acid (H3PO4)?

-7
+1
+5
+7

The question involves calculating the enthalpy of reaction (ΔH) for the conversion of SiCl4 and H2O to SiO2 and HCl, focusing on the energy changes associated with bond breaking and formation during this chemical reaction.

The question refers to the enthalpy of reaction for the process in which silicon tetrachloride (SiCl4) reacts with water (H2O) to produce silicon dioxide (SiO2) and hydrochloric acid gas (HCl). This reaction can be represented as:

SiCl4(l) + 2H2O(l) → SiO2(s) + 4HCl(g)

To understand the enthalpy change (ΔH) of this reaction, one needs to consider the bond energies involved in breaking and forming chemical bonds during the reaction. The process of calculating ΔH for a reaction involves understanding the energy required to break bonds in the reactants and the energy released by forming bonds in the products.

Silicon tetrachloride is a covalent tetrahedral molecule that engages in reactions leading to the formation of silicon dioxide and hydrochloric acid gas when exposed to water. This type of reaction is exothermic if the energy released in forming the products' bonds is greater than the energy required to break the reactants' bonds. Calculating the exact ΔH would require specific values of bond energies, which are not provided here.

The enthalpy of reaction for SiCl₄(l) + 2H₂O(l) → SiO₂(s) + 4HCl(g) is calculated to be -66 kJ.

This involves using the enthalpies of formation for each compound. The result indicates an exothermic reaction.

To determine the enthalpy of reaction for the given chemical equation, we need to use the known enthalpies of formation for each compound involved:

The enthalpy of the reaction (ΔHrxn) is calculated using the formula:

ΔHrxn = ΣΔHf(products) - ΣΔHf(reactants)

Assuming standard enthalpy of formation (ΔHf) values as follows:

The enthalpy of the reaction would be calculated as:

ΔHrxn = [(-910) + 4(-92)] - [(-640) + 2(-286)] kJ

That simplifies to:

ΔHrxn = (-910 - 368) - (-640 - 572) kJ = -1278 + 1212 kJ = -66 kJ

Thus, the enthalpy of the reaction is -66 kJ.

Answer:

Na₂S + FeBr₂ → 2NaBr + FeS(s)

MgSO₄ + CaCl₂ → MgCl₂ + CaSO₄(s)

AgNO₃ + NaCl → AgCl(s) + NaNO₃

Explanation:

You must recall the pertinent solubility rules:

Na₂S + FeBr₂ → 2NaBr + FeS(s)

NaBr is soluble (Rule 1). FeS is insoluble (Rule 5), so a precipitate forms.

MgSO₄ + CaCl₂ → MgCl₂ + CaSO₄(s)

MgSO₄ is soluble (Rule 3). CaSO₄ is insoluble (Rule 4), so a precipitate forms.

AgNO₃ + NaCl → AgCl(s) + NaNO₃

NaNO₃ is soluble (Rule 1). AgCl is insoluble (Rule 3) so a precipitate forms.

LiOH + NH₄I → LiI + NH₄OH and 2NaCl + K₂S → Na₂S + 2KCl

All products are soluble (Rule 1), so these are not precipitation reactions.

HEY I GOT YO ANSWER

THE ANSWERS ARE A B AND DA LAST ONE

Which of these measurements is expressed as three significant figures?  

C. 4.20 g

use baby oil...it helps get the oil paint off.  I think it is hard because it is heavier than water and it sticks to your skin and also the water and oil don't mix like other things so it makes it alot harder. use baby oil and wash.

Well it depends, if you add heat to ice it will melt, if you add heat to water it will  evaporate.

Hope it helps!

Why hello there, Lithommie

Your question: can someone explain to me what happens when thermal energy is added to a state of matter?

My answer:

Very good question

lets take a look at what happens when thermal energy is added to a state of matter.

In this case lets look at a football game, at the beginning of the game the players represent the state SOLID the scores 0-0 and the heat is on. Remember the players are solid and when they are melting into a liquid by the end of the game and the players are mixing through the field and collapsing with one another and by the end of the game they become liquid.

Do you understand more clearfully? If you add heat to ice( the solid ) it melts and becomes water( The liquid )

IMPORTANT: If my answer helped please mark me as brainliest thank you and have the best day ever!

               Adding 15 g of Flubber with 85 g of inert solvent will result in the formation of 15 % solution.

              W/V %  =  15 %

              Weight of Flubber  =  ?

              Weight of Solution  =  ?

              Let's suppose we are going to prepare a 100 mL solution. The using following formula we can calsulate the amount of Flubber required.

              W / W %  =  (Weight of Flubber ÷ Weight of Solution) × 100

Putting values,

              15 %  =  (Weight of Flubber ÷ 100 g) × 100

Solving for Weight of flubber,

              Weight of Flubber  =  (15 × 100 g) ÷ 100

              Weight of Flubber  =  15 g

Hence, taking 15 g of Flubber and adding it to 85 g of solvent will result in the formation of 15% Flubber solution.

Final answer:

To create a 15% solution of flubber, combine 15 grams of flubber with sufficient solvent to make 100 milliliters of solution, ensuring the flubber is fully dissolved and the total volume reaches 100 milliliters.

Explanation:

How to Make a 15% Solution of Flubber

To make a 15% solution of flubber, you would typically mix 15 grams of flubber (the solute) with enough solvent to make a total solution volume of 100 milliliters. The steps to creating this solution are as follows:

Weigh 15 grams of flubber using a scale.

Transfer the flubber into a container, such as a beaker.

Add a solvent, usually water, to the beaker.

Stir the mixture until the flubber is completely dissolved.

Continue adding water until the total volume of the solution is 100 milliliters.

Remember that when making a solution, the percentage is calculated by the mass of the solute divided by the total volume of the solution, and then multiplied by 100 to get the percentage. Therefore, a 15% solution of flubber in this case means you have 15 grams of flubber in every 100 milliliters of solution.

]

c group A is the correct answer

Answer:

The answer is D "in the middle"

Explanation:

I did the test and got 100%

Have a great day! :)

[tex]\boxed{2172.1{\text{ kg}}}[/tex] of sodium carbonate must be added to neutralize [tex]2.01 \times {10^3}{\text{ kg}}[/tex] of sulfuric acid solution.

Further Explanation:

Stoichiometry:

Theamountof species present in the reaction is determined with the help of stoichiometryby the relationship between reactants and products. It is used to determine the moles of a chemical species when moles of other chemical species present in the reaction is given.

Balanced chemical reaction between sodium carbonate and sulphuric acid is as follows:

 [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}} + {{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}} \to {\text{N}}{{\text{a}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}} + {{\text{H}}_{\text{2}}}{\text{O}} + {\text{C}}{{\text{O}}_{\text{2}}}[/tex]

According to stoichiometry of reaction, one mole of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] reacts with one mole of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] to produce one mole of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex], one mole of  [tex]{{\text{H}}_{\text{2}}}{\text{O}}[/tex] and one mole of [tex]{\text{C}}{{\text{O}}_{\text{2}}}[/tex]. So stoichiometric ratio between [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] and [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] is 1:1.

The formula to calculate number of moles of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] is as follows:

[tex]{\text{Moles of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}} = \dfrac{{{\text{Mass of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}{{{\text{Molar mass of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}[/tex]                                             …… (1)

Substitute [tex]2.01 \times {10^3}{\text{ kg}}[/tex] for mass of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] and 98.079 g/mol for molar mass of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] in equation (1).

[tex]\begin{aligned}{\text{Moles of }}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}} &= \left( {\frac{{2.01 \times {{10}^3}{\text{ kg}}}}{{{\text{98}}{\text{.079 g/mol}}}}} \right)\left( {\frac{{{{10}^3}{\text{ g}}}}{{1{\text{ kg}}}}} \right)\\&= 20493.7{\text{ mol}}\\\end{aligned}[/tex]  

Since one mole of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] reacts with one mole of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex], 20493.7 moles of [tex]{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}[/tex] reacts with 20493.7 moles of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex].

The formula to calculate mass of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] is as follows:

[tex]{\text{Mass of N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}} = \left( {{\text{Moles of N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}} \right)\left( {{\text{Molar mass of N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}} \right)[/tex]                …… (2)

Substitute 20493.7 mol for moles of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] and 105.9888 g/mol for molar mass of [tex]{\text{N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}}[/tex] in equation (2).

[tex]\begin{aligned}{\text{Mass of N}}{{\text{a}}_{\text{2}}}{\text{C}}{{\text{O}}_{\text{3}}} &= \left( {{\text{20493}}{\text{.7 mol}}} \right)\left( {{\text{105}}{\text{.9888 g/mol}}} \right)\left( {\frac{{{{10}^{ - 3}}{\text{ kg}}}}{{1{\text{ g}}}}} \right)\\&= 2172.1{\text{ kg}}\\\end{aligned}[/tex]  

Learn more:

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Mole concept

Keywords: stoichiometry, Na2CO3, H2SO4, Na2SO4, CO2, H2O, balanced chemical reaction, 1:1, one mole, stoichiometric ratio, 2172.1 kg.

To neutralize the sulfuric acid spill, you need to use sodium carbonate (Na2CO3). For every 2 moles of sulfuric acid, you need 2 moles of sodium carbonate. Therefore, to neutralize 2.01 x 10³ kg of sulfuric acid solution, you would need an equal mass of sodium carbonate.

To neutralize the sulfuric acid spill, you need to use sodium carbonate (Na2CO3). The balanced equation for the reaction between sulfuric acid and sodium carbonate is:

2 NaHCO3(aq) + H2SO4(aq) → Na2SO4(aq) + 2 CO2(g) + 2 H2O(l)

From the equation, you can see that for every 2 moles of sulfuric acid, you need 2 moles of sodium carbonate. Therefore, to neutralize 2.01 x 10³ kg of sulfuric acid solution, you would need an equal mass of sodium carbonate. So, you would need 2.01 x 10³ kg of sodium carbonate.

https://brainly.com/question/10103823

#SPJ3

2.57 kilograms = 2570 grams

i think this is standard form but i don't know 100%

Remember that there are 1000 grams in 1 kilogram.

Multiply 1000 grams with 2.570 kilograms

1000 x 2.570 = 2570

2570 grams are in 1 kilogram

hope this helps

Answer: The number of moles of sugar that is used are 0.055 moles.

Explanation:

We are given:

Mass of 1 mole of sugar = 342 g

Mass of sugar used = 19 g

So, by applying unitary method, we get:

342 grams of sugar is making 1 mole

So, 19 grams of sugar will make = [tex]\frac{1mol}{342g}\times 19g=0.055mol[/tex]

Hence, the number of moles of sugar that is used are 0.055 moles.

Answer:

condense

Explanation:

If the relative humidity is high and the temperature drops, water vapor may condense as pressure increases with decrease in temperature.

Pressure is defined as the force applied on an object perpendicular to it's surface per unit area over which it is distributed.Gauge pressure is a pressure which is related with the ambient pressure.

There are various units by which pressure is expressed most of which are derived units which are obtained from unit of force divided by unit of area . The SI unit of pressure is pascal .

It is a scalar quantity which is related to the vector area element with a normal force acting on it.It is distributed over solid boundaries and across arbitary sections of fluid normal to the boundaries at every point.

Learn more about pressure,here:

https://brainly.com/question/18107358

#SPJ2

Lead has a higher density

Using the formula as frequency = speed of light/ wavelength of light

f = c/λ

Where c = [tex]3.0 X 10^{8}[/tex] m/s and λ = [tex]5.4 X 10^{-4}[/tex] m

Substituting in above formula we get,

∴ f = [tex]\frac{3.0 X 10^{8}m/s}{5.4 X10^{-4}m}[/tex]

∴f = 5.55 X [tex]10^{13}[/tex] Hz

Answer:

55x 1013x i think im not too sure

Explanation:

Hydrogen bonds are intermolecular (“between-molecule”) bonds, rather than intramolecular (“within-molecule”) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weaker as chemical bonds. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds.

Hydrogen bond is weaker than ionic and covalent bonds. Example: Water molecules are held to each other by intermolecular forces of attraction. Covalent bonds are the strongest bonds, meaning that atoms are actually held together by the physical sharing of electrons.

Final answer:

A copper penny turns green due to a chemical change, which is the oxidation of copper resulting in the formation of a green patina that protects the penny from further corrosion.

Explanation:

When a copper penny turns green after being exposed to air and moisture, it is due to a chemical change. This is a process similar to what happens to copper surfaces like the Statue of Liberty, where the oxidation of copper leads to the formation of a green patina. The chemical reaction for the oxidation can be represented by the equation 2 Cu(s) + O₂(g) → CuO(s), where copper (Cu) reacts with oxygen (O₂) to form copper oxide (CuO). The green color is attributed to additional reactions that form compounds like copper carbonate and copper sulfate, which comprise the patina. This patina acts as a protective layer, preventing further corrosion through a process known as passivation.

Answer: High energy and Low wavelength.

Explanation: We are given an electromagnetic wave having high energy, so by using Planck's equation:

[tex]E=h\nu[/tex]

where, E = energy

h = Planck's constant

[tex]\nu[/tex] = frequency

here, Energy and frequency follow direct relation and hence high frequency means high energy.

and [tex]\nu=\frac{c}{\lambda}[/tex]

[tex]\nu[/tex] = Frequency

c = speed of light

[tex]\lambda[/tex] = wavelength

Here, the frequency is inversely related to the wavelength, hence high frequency means low frequency.

Ionic bonds are formed by the differences in the electronegativities of the elements. Yes, sodium, and fluorine will form ionic bonds. Thus, option A is correct.

Ionic bonds are the category of chemical bonds that are formed by the complete transfer of the electron from one atom to another resulting in the formation of the cation and the anion. This sharing occurs through the difference in electronegativity.

If the electronegativity difference is more than 1.5 to 1.7 then, the electron sharing occurs by the virtue of the valence shell.

Given,

Electronegativity of fluorine (F) = 3.98

Electronegativity of sodium (Na) = 0.93

The differences are calculated as:

= Electronegativity of fluorine - Electronegativity of sodium

= 3.98 - 0.93

= 3.05

As 3.05 > 1.7 it will form the ionic bond.

Therefore, yes sodium and fluorine form an ionic bond.

Learn more about the ionic bonds, here:

https://brainly.com/question/977324

#SPJ2

Final answer:

The difference in electronegativity between Na and F is large enough to predict the formation of an ionic bond. Sodium, being a metal, donates an electron to fluorine, a nonmetal, resulting in the creation of oppositely charged ions that attract each other.

Explanation:

When predicting whether a pair of elements will form an ionic bond, the key factor to consider is the electronegativity difference between the two elements. Ionic bonds generally form when one element (typically a metal) transfers one or more valence electrons to another element (typically a nonmetal), resulting in the formation of ions that are oppositely charged and attract each other due to electrostatic forces. In the case of sodium (Na) and fluorine (F), the electronegativity difference is indeed large enough to favor the formation of an ionic bond.

Electronegativity differences greater than approximately 1.7 tend to lead to ionic bonding. Sodium (Na), a metal, has a much lower electronegativity compared to fluorine (F), which is a highly electronegative nonmetal. The difference in electronegativity between Na and F is roughly 3.0, which is significantly greater than the threshold value for ionic bonding, indicating that Na and F will form an ionic bond.

Answer :

(1) The correct option is, Their components can be separated by physical processes.

(2) In the given image, image 1, 2 and 4 belong to the same element.

(3) The correct option is, kelvin

Explanation :

For 1 :

Heterogeneous mixtures : It is a mixture that appears non-uniformly throughout the solution and the particle size or shapes are also different.

Homogeneous mixtures : It is a mixture that appears uniformly throughout the solution and the particle size or shapes are not different.

The similarity between the homogeneous and heterogeneous mixture is that their components can be separated by physical processes. As the mixture of salt and water is homogeneous mixture which can be separated by the evaporation and the mixture of sand and water is heterogeneous mixture which can be separated by the filtration. Evaporation and filtration is a physical processes.

For 2 :

The element having the same number of protons are called as isotopes of the same element.

From the image given, three of the structures justify the above statement.

The three atomic models are model 1, model 2 and model 4.

For 3 :

S.I : It is defined as a scientific method to express the magnitude of the several basics units.

There are seven basic units in the system from which the other units are derived.  The seven base unit are, meter for length, kilogram for mass, second for time, ampere for current, kelvin for temperature, mole for amount of substance and candela for intensity.

As we know that the temperature can be measured in, degree Celsius, degree Fahrenheit and kelvin.

Thus, the SI unit of temperature is, kelvin

All the alkali metals react vigorously with cold water. In each reaction, hydrogen gas is given off and the metal hydroxide is produced. The speed and violence of the reaction increases as you go down the group. HOPE THIS HELPS!! :)

Answer:

There are 3 sig figs

Explanation:

Sig figs are the amount of figures counting from the left side of the number until you reach the first zero. Starting from the left, I counted one, three, and six. That's 3 numbers, and therefore, that's how we got our answer. The only exception is when there is a decimal. Then all the numbers before the decimal, despite whether or not they're zeros, are sig figs.

Answer:

3 significant figures

Explanation:

The significant figure is such that every number after it is zero. As such, when a number is given to be rounded to a x significant numbers, the count starts from the left with the first number on the left being the first significant number and others following through i.e the next being the second significant number.

However, to round off to x significant number, we consider the number in the x+1 position. If the number is up to 5, it will be rounded ( as well as every other numbers to the right) to zero but 1 will be added to the number in the x position.

Given the theory, 136,000 ml has 3 significant figures.

Final Answer:

The experiment aimed to investigate the impact of environmental factors on plant growth. The results indicated a significant correlation between sunlight exposure and the growth rate of the plants.

Explanation:

In this experiment, the focus was on understanding how environmental factors influence plant growth.

The results revealed a noteworthy relationship between the amount of sunlight the plants received and their growth rate.

This finding aligns with established knowledge in botany, highlighting the crucial role sunlight plays in photosynthesis, a key process driving plant development.

The experimental design likely controlled variables such as soil quality and water supply to isolate the impact of sunlight.

This approach enhances the validity of the results, allowing for a more accurate assessment of the specific influence of sunlight on plant growth.

The observed correlation underscores the importance of considering environmental factors in agricultural and ecological contexts, emphasizing the need for appropriate sunlight exposure to optimize plant productivity.

In conclusion, the experiment's results contribute valuable insights into the interplay between environmental factors and plant growth, with sunlight emerging as a key determinant.

Understanding these relationships is vital for informed decision-making in agriculture and ecosystem management.

The correct answer is 'Replicable results and empirical data'.

For science to be reliable, the scientific method must be replicable and the data must be empirical.

When scientists publish their work they write enough data so that scientists all over the world can replicate their experiment and get same results.

Also the scientific method is based on empirical data which is based on direct observation of the world and is contrary to hypothesis that do not rely on facts.

Answer: The correct answer is Option C.

Explanation:

Oxidation reaction are the reactions in which an element or compound looses electrons and the element that looses electrons is known as oxidized species. The oxidation state of the species is increased for these kind of reactions.

[tex]X\rightarrow X^{n+}+ne^-[/tex]

Reduction reaction are the reactions in which an element or compound gains electrons and the element that gains electrons is known as reduced species. The oxidation state of the species gets reduced for these kind of reactions.

[tex]X^{n+}+ne^-\rightarrow X[/tex]

For the given chemical reaction:

[tex]4Li+2CoO\rightarrow 2Co+2Li_2O[/tex]

On reactant side:

Oxidation state of lithium = 0

Oxidation state of cobalt = +2

Oxidation state of oxygen = -2

On product side:

Oxidation state of lithium = +1

Oxidation state of cobalt = 0

Oxidation state of oxygen = -2

As, oxidation state of lithium is increasing, it is loosing electrons and thus it is undergoing oxidation reaction and the oxidation state of cobalt in reducing, it is gaining electrons and thus it is undergoing reduction reaction .

Hence, the correct answer is Option C.

Answer:

C. Li

Explanation:

Answer: An igneous rock that cools rapidly is made of really small mineral crystals.

Explanation:

The layers inside the earth are hot enough to melt a rock. The liquid or molten rock is known as magma.

When a molten rock cools and solidifies, it results in the formation of an igneous rock.

The slow cooling of magma will result in the formation of an igneous rock with large crystals. Whereas, rapid cooling of lava will result in the formation of an igneous rock with small crystals.

Thus, it can be concluded that an igneous rock that cools rapidly is made of really small mineral crystals.

protons= 53

electrons= 54

neutrons= 55

Answer:

d

Explanation: