1. How much heat is required to melt 25.0 g of ice at 0°C?

Answer:

B) 101,025

Explanation:

1000g * 0.449 J/g Celsius * 225 Celsius = 101,025

I got 225C from 250C - 25C

Answer: mass of electron is

9.10938356 × 10^-31 kilograms

Explanation:

Answer:

thunderstorms

Explanation:

Answer:

C. democritusm John dalton, JJ Thomason, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

The correct order of the scientists in order of their work related to the

structure of an atom from earliest to most recent include Democritus, John

Dalton, JJ Thomson, Ernest Rutherford, Neils Bohr, and Erwin Schrodinger.

Democritus was regarded as one of the earliest scientist who first proposed

atomic theory around 460 BC which was then modified and used by others

such as John Dalton, JJ Thomson, Ernest Rutherford and Neils Bohr.

The most recent of them all was Erwin Schrodinger which was  the wave

equation for electron movements in the 20th century.

Read more on https://brainly.com/question/20339664

Answer:

a) 34 g

b) 18.33 moldm^-3

Explanation:

a) The equation of the reaction is;

2NaNO3----------> 2NaNO2 + O2

Let us recall that 1 mole of a gas occupies 22.4 dm^3. Since 1 mole of O2 is produced in the reaction, we can write;

2 moles of NaNO3 yields 22.4 dm^3 of O2

x moles of O2 yields 4.5 dm^3 of O2

x = 2 * 4.5/22.4

x = 0.4 moles of NaNO3

But number of moles = mass/molar mass

molar mass of NaNO3 = 85 g/mol

Mass of NaNO3 = 0.4 moles * 85 g/mol

Mass of NaNO3 = 34 g

b)

Number of moles in 200g of HCl = mass/molar mass

molar mass of HCl = 36.5 g/mol

Number of moles = 200g/36.5 = 5.5 moles

From;

Number of moles = concentration * volume in dm^3

concentration = Number of moles/ volume in dm^3

But volume = 300 cm^3 or 0.3 dm^3

concentration = 5.5/0.3 = 18.33 moldm^-3

Answer:

C4H2O6

Explanation:

Answer:

this is the answer explanation of previous question. as what you say in comment i do that

Answer:

J.J Thompson make use of creativity to explain cathode ray tube experiment.

Also, creativity was used by Daltons to explain Joseph Proust's work.

Explanation:

This problem is all about the the beginning part of chemistry that is the atomic  theory. The atomic theory was starts from the time of people like Democritus and down to people like J.J Thompson and John Dalton. Although it has been registered and credited that Dalton is the father of atomic theory many people has also worked on it before him for instance person like Joseph Proust. The reason behind this because some works that has been done by other people such as Democritus[who was the first person to start atomic studies] does not have any scientific evidence.

Creativity is needed when it concerns scientific research and investigation. This is what scientists such as John Daltons and J.J Thompson have used. J.J Thompson make use of creativity to explain cathode ray tube experiment. Also, creativity was used by Daltons to explain Joseph Proust's work.

Answer:

a

Explanation:

it is the concentration of the hydrogen ion, more hydrogen ion more acidic less hydrogen ion less acidic and alkaline.

Answer:

Such was the case with the concept of pH, introduced in 1909 by Søren Sørensen as a convenient way of expressing acidity—the negative logarithm of hydrogen ion concentration.Jan 8, 2018

Profession: Chemist

Answer:

D

Explanation:

it doesn't matter how many protons k has all the answers have electron with the positive charge when is negative the question is trying to distract you D is the only one that would use the electrons sign correctly

Answer:

a. bond angles c. bond length

Explanation:

Models are abstractions of the real world. They are used to present either real or hypothetical situations either visually, graphically or through mathematical expressions.

Answer:

ok thats cool good luck with that and always remember God is there for you :)

Answer:

yeah

Explanation:

in every situation we should trust God

Answer: Option 1

Explanation: hopes it helps

Valence Shell Electron Pair Repulsion (VSEPR) theory is employed in prophesying the geometrical organisation of the specific molecule with the aid of electron sets found encompassing the atom.

The correct answer is:

Option A. If a molecule has four pairs of electrons, it will always have a tetrahedral structure.

This can be explained as:

Therefore atom containing four pairs of electrons will have a tetrahedral shape.

To learn more about VSEPR theory follow the link:

https://brainly.com/question/12775505

Answer:

When zinc metal is reacted with hydrochloric acid, hydrogen gas is released and an aqueous solution of zinc chloride is produced. ... It is important that all of the zinc used be reacted and that large excess amounts of hydrochloric acid not be used.

Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. Whereas, hydrated and aqueous forms of zinc chloride are prepared by treating zinc with hydrochloric acid. Zinc metal could either be in the form of zinc sulfide or zinc oxide

Have a nice Day , Hope this helped you I would appreciate it if you could mark my answer brainliest

Merry Christmas

Answer: Anhydrous zinc chloride is synthesized by treating zinc with hydrogen chloride. ... Zinc metal could either be in the form of zinc sulfide or zinc oxide. ZnS(s) + 2 HCl(aq) → ZnCl2(aq) + H2S(g) There are impurities present in zinc chloride samples due to hydrolysis.

got this from goo.gle

Hope this helps.......... Stay safe and have a Merry Christmas!!!!! :D

Answer:

kindly check the explanation section.

Explanation:

The two ions given in the question above that is Dihydrogenphosphate, H2PO4- and HPO42- are so important when it concerns buffering. During intracellular pH balancing the ions that is H2PO4- and HPO42- reacts with OH⁻ and H⁺ respectively. The equation for the chemical reaction is given below for both ions.

H₂PO₄⁻ + OH⁻  < =====================================> HPO₄²⁻ + H₂O.

HPO₄²⁻ + H⁺ <===========================================> H₂PO₄⁻.

Answer:

See the answer below

Explanation:

When magnesium is heated in air, the element combines with oxygen to form a compound known as magnesium oxide according to the following equation:

    [tex]2Mg(s) + O_2 (g)--> 2MgO (s)[/tex]

Hence, the product formed - a combination of magnesium and the oxygen component of air - is heavier than the original magnesium ribbon.

On the other hand, potassium manganate (7) is heated in air and decompose to form potassium manganate (6), manganate oxide, and oxygen gas according to the following equation:

    [tex]2KMnO_4 --> K_2MnO_4 + MnO_2 + O_2[/tex]

Hence, the final product formed is lighter than the original product because oxygen gas has been evolved.

Answer:

During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide. However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off.

Explanation:

During the heating of magnesium in air, it gains mass with the addition of oxygen present in air to form the oxide.

The equation for the reaction is given below:

2Mg(s) + O2(g) ---> 2Mg0

The molar mass of the magnesium metal is 24.0 g while the mass of the magnesium oxide is 40.0 g. The total mass of the metal before heating is 24 × 2. + 32 = 48.0 g. The total mass after heating = 48 + 32 = 80.0 g. Therefore, there is an increase in mass.

However, during the heating of potassium manganate (vii), it decomposes or breaks down to simpler products and oxygen gas is given off. The equation for the reaction is given below;

2KMnO4(s) ----> K2MnO4(s) + MnO2(s) + O2(g)

With the evolution of oxygen gas, there's a loss in mass of potassium manganate (vii). Molar mass of KMnO4 is 158.0 g while the mass of K2MnO4 is 197.0 g and that of MnO2 is 87.0 g. The total mass on the right hand side is 2 × 158 = 316.0 g. The total mass on the left-hand side with the exception of the gas evolved is 284.0 g. Therefore, there is a loss in mass.

Answer:

C = 9460 Kj

Explanation:

Given data:

Mass of copper = 2kg

Latent heat of vaporization = 4730 Kj/Kg

Energy required to vaporize 2kg copper = ?

Solution:

Equation

Q= mLvap

by putting values,

Q= 2kg ×  4730 Kj/Kg

Q = 9460 Kj

Answer:

Ore

hope this helps

thanks for the points

Answer:

See explanation

Explanation:

1) The formula of the compound is Fe2(SO4)3. There are two ion atoms in any formula unit as we can see here. Three sulphate ions are attached to iron. Each iron ion carries a +3 charge as we saw in the formula. The total positive charge in each formula unit is +6.

Changing a subscript in a correctly written chemical formula changes the formula so that it no longer represents the compound it previously represented. Hence FeSO4 is a different compound from Fe2(SO4)3.

Answer:

Ae4

Explanation:

which virtually showed the reaction between group 4 element and group 7 element

Answer:

Chemicals should involve information about properties and reactants.

Answer:

V = 53.83 L

Explanation:

Given data:

Number of moles = 2.00 mol

Temperature = 45°C (45+273 = 318 K)

Pressure = 98.6 KPa (98.6/101 = 0.97 atm)

Volume of gas = ?

Solution:

PV = nRT

R = general gas constant = 0.0821 atm.L/mol.K

0.97 atm × V = 2.00 mol × 0.0821 atm.L/mol. K × 318 K

V = 52.22 atm.L/0.97 atm

V = 53.83 L

The equilibrium constant K : 0.089

Given

Reaction

H₂O(g)+Cl₂O(g)⇔2HClO(g)

[H2O]=0.077M,[Cl2O]=0.077M,[HClO]=0.023M

Required

the equilibrium constant

Solution

The equilibrium constant or Kc is the value of the concentration product in the equilibrium state of the substance in the right segment divided by the product of the substance in the left section, each of which has a reaction coefficient raised  

[tex]\tt K=\dfrac{[HClO]^2}{[H_2O][Cl_2O]}\\\\K=\dfrac{0.023^2}{0.077\times 0.077}\\\\K=0.08922[/tex]

The balanced equation :

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

Given

The following reaction(combustion of Propanol) :

C₃H₇OH+O₂⇒ CO₂ +H₂O​

Required

Balanced equation

Solution

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:  

• 1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.  

• 2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product  

• 3. Select the coefficient of the substance with the most complex chemical formula equal to 1  

1. Give coefficient

C₃H₇OH+aO₂⇒ bCO₂ +cH₂O​

2. Make an equation

C, left=3, right=b⇒b=3

H, left=8, right=2c⇒2c=8⇒c=4

O, left=1+2a, right=2b+c⇒1+2a=2b+c⇒1+2a=2.3+4⇒1+2a=10⇒2a=9⇒a=9/2

The equation becomes

C₃H₇OH+9/2O₂⇒ 3CO₂ +4H₂O x 2

2C₃H₇OH+9O₂⇒ 6CO₂ +8H₂O​​

in one molecule we have one oxygen atom so we will have 4 oxygen atoms in 4 molecules