which of the following is a physical change? 1.burning paper 2.grinding wheat 3.electrolysis of water 4.cooking rice​

Answer:

- The dry ice is cooling the ground it rests upon as heat is transferred from the ground to the dry ice.

Explanation:

The above statement correctly elaborates the process of using dry ice to develop the appearance of fog. When the dry ice is placed on the ground, the heat of the ground is transferred to the dry ice. This will result in the increase in the kinetic energy of the CO2 molecules. Thus, the solid will directly convert into gas and it will lead to the formation of gas in the air. Since CO2 possesses a higher density, it will look like fog and thus, giving the perfect shot for the fog scene.

Answer:

transition state is a point in which electrons been removed from the atom

Answer:

The highest energy structure in the reaction coordinate.

Explanation:

Answer:

a. H2O: dihydrogen monoxide

b. PCl5: Phosphorus pentachloride

c. SiF4: Silicon tetrafluoride

d. N20: dinitrogen oxide

Answer:

No and Yes

Explanation:

it depends bc its an ionic compound, therefore can't conduct electricity when SOLID, BUT unless it DISSOLVES in water it can conduct

Answer:

D. is the answer which is copper is a conductor because it's valency can move from atom to atom.

Answer:

Answer is 2nd

Explanation:

some energy is transformed into mass

Answer: The labelling of each molecule is listed below:

B.) alkyne

C.) Alkane

D.) alkyne

I.) alkene

Explanation:

In organic chemistry, if an organic compound contains atoms joined only by single covalent bonds, the compound is said to be saturated. The ALKANES are said to be saturated hydrocarbons. For example butane and hexane that is shown in option F and G respectively. If an organic compound contains carbon atoms joined by double or triple covalent bonds, the compound is said to be unsaturated. For example Octene and butyne as seen in option E and H respectively.

Furthermore, hydrocarbons possess8g a set of carbon-carbon double covalent bonds,>C=C<, in their carbon chains form the homologous series called ALKENES while those possessing a set of carbon-carbon triple covalent bond in their carbon chains form the ALKYNE series

From the questions above, a more informative formula known as the structural formula is used to represent the various organic substances. The formula indicates how the atoms are arranged within the molecule of a substance. A structural formula is usually shown as a planar for convenience and does not imply a flat molecule. It shows the actual arrangement of the atoms in space and the angles between the bonds. Therefore options C, D and I are alkane,alkyne and alkene respectively.

Answer:

the valence of S is -2. For FeS to be neutral the valence of Fe used must be +2

and since Iron (II) has its valency 2, FeS will be Iron (II) Sulfide.

Answer:

The correct answer is - butanoic acid

Explanation:

An empirical formula is the general formula or base formula that is the simplest positive integer ratio of atoms present in a compound. The empirical formula is specific to specific compounds or types of compounds.

Among the given options, the empirical formula C2H4O is butanoic acid as the molecular formula of butanoic acid is - C4H8O2 which is multiple of C2H4O. Other compounds have different than this empirical formula.

Answer:

c hierro

no se la otra sorry

Answer:

Al2O3 + 6HCl ==> 2AlCl3 + 3H2O ... balanced equation

moles Al2O3 present = 30.0 g x 1 mol/101.96 g = 0.294 moles

moles HCl present = 30 g HCl x 1 mol/36.5 g = 0.822 moles HCl

HCl is LIMITING as it takes 6 moles HCl for each 1 mol Al2O3 and here that is not enough. It will run out first.

Now, using the limiting reactant, we find the moles and mass of AlCl3 that can be formed.

0.822 moles HCl x 2 moles AlCl3/6 moles HCl = 0.274 moles AlCl3 formed

mass of AlCl3 = 0.274 moles AlCl3 x 133 g/mole = 36.4 g AlCl3 formed

Answer:

beryllium is the answer.

I hope this will help you

Answer:

oh it's easy

Explanation:

Take the hydrate

N

a

2

S

2

O

3

∙

5

H

2

O

. Are there ionic forces between the

N

a

+

and the

S

2

O

2

−

3

and ion-dipole forces between the cation/anions and the water?

Answer:

1. Combination (Synthesis) reaction

A + B → AB

2. Decomposition reaction

AB → A + B

3. Displacement reaction

A + BC → AB + C

4. Double displacement reaction

AB + CD → AD + BC

5. Combustion reaction

[tex]CH_{4} + 20_{2} → CO_{2} 2Hx_{2} O[/tex]

A combination reaction, also known as a synthesis reaction, is a reaction in which two or more substances combine to form a single new substance. Combination reactions can also be called synthesis reactions.

A decomposition reaction is a reaction in which a compound breaks down into two or more simpler substances.

A single-replacement reaction is a reaction in which one element replaces a similar element in a compound.

A double-replacement reaction is a reaction in which the positive and negative ions of two ionic compounds exchange places to form two new compounds.

A combustion reaction is a reaction in which a substance reacts with oxygen gas, releasing energy in the form of light and heat. Combustion reactions must involve  O2 as one reactant. The combustion of hydrogen gas produces water vapor

Explanation: Hope this helps and good luck :))

Answer:

Answer to the following question is as follows;

Explanation:

Alkynes' vapour pressure and normal boiling points are altered when chain length grows, since vapour pressure rises while boiling point falls.

Vapour pressure always include pressure entered by vapour with its condensed phase, pressure include molecules force of attraction include vapour

Answer:

TIMED HELP ASAP

19.11 g of MgSO₄ is placed into 100.0 mL of water. The water's temperature increases by 6.70°C. Calculate ∆H, in kJ/mol, for the dissolution of MgSO₄. (The specific heat of water is 4.184 J/g･°C and the density of the water is 1.00 g/mL). You can assume that the specific heat of the solution is the same as that of water.

Answer:

-21.03 kJ/mol

Explanation:

∆H is enthalpy. Enthalpy is the total heat content of a system.

So we can establish that ∆H = q (heat)

The formula for heat (q)

q = cm∆T

c = specific heat capacity

m = mass of substance

∆T= change of temperature

Since we are calculating the enthalpy of the SOLUTION. We must account for both the mass of water and the mass of MgSO₄ in our q formula.

All you gotta do is plug and chug at this stage.

∆H = q     = cm∆T = (4.184)(19.11+100.0)(6.70) = 3338.986808 Joules

We have now calculated the heat (aka enthalpy) of the solution.

BUT

Remember! The problem asked for enthalpy in kj....

Use this conversion factor.

1000 J = 1 kJ

3338.986808 Joules * 1kJ/1000 J = 3.338986808 kJ

We were asked to find ∆H for the dissolution of MgSO4  in units of kj/mol so we are not finished.

Take the grams of MgSO4 in the problem  and convert it into moles using its molar mass.

MgSO4 molar mass = 120.3676 g

1 mol = 120.3676 g MgSO4   <---- Use this as a conversion factor

19.11 g MgSO4 * 1 mol MgSO4/120.3676 g = 0.15876365 mol MgSO4

Now that you've calculated the moles of MgSO4 in this solution. You can divide your heat by it.

q dissolution = 3.338.986808 kJ/ 0.15876365 mol =  21.03 kj/mol

Note that the problem tells us that the temperature of water increases.

This means that the water is experiencing an endothermic process (heat is being absorbed from MgSO4) . Mathematically, this would be indicated by a positive sign. ---> +q

We can assume MgSO4 is losing heat as it is placed into the water. It is experiencing an exothermic process (heat is being lost).  Mathematically, this would be indicated by a negative sign. ----> -q

So if we're calculating the enthalpy for the dissolution of MgSO₄ ....the value we've arrived at must be negative.

Answer

∆H = 21.03 kj/mol :)))))

I hope that helped...I feel like my explanation was a bit convoluted.

Answer:

Lumayan poin gratis...

gw gatau lu pake bahasa apaan njink

Protons are positively charged particles that are located inside the nucleus at the center of the atom. Protons have a mass of 1 amu or atomic mass unit.

Electrons are negatively charged particles found outside the nucleus. Electrons have a mass of approximately 0 amu or atomic mass unit.

hope it helps :)

please mark brainliest!!!

Answer:

B. it's water of crystallization.

the water of crystallization, that is the number of molecules of water attached to One Copper atom gives blue color to the hydrated salt (CuSO4.5H2O)

The question is incomplete, the complete question is;

.On heating 12.4 g of copper (II) carbonate in a crucible only 7.0g of copper (II) oxide was produced. What was the % yield of copper (II) oxide ? [Cu=64,C=12,O=16]

Answer:

87.5%

Explanation:

CuCO3 -------> CuO + CO2

Number of moles of CuCO3 = 12.4g/123.55 g/mol = 0.1 moles

Since the reaction is 1:1,

Mass of CuO produced = 0.1 moles × 80g/mol = 8 g

Hence,

% yield = actual yield/theoretical yield × 100

% yield = 7/8 × 100

% yield = 87.5%

Answer:

1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.

Explanation:

The balanced reaction is:

Mg+ 2 HCl → MgCl₂ + H₂

By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:

Being the molar mass of each compound:

By reaction stoichiometry, the following mass amounts of each compound participate in the reaction:

Then you can apply the following rule of three: if by stoichiometry 24.31 grams of Mg produces 2 grams of H₂, 12.5 grams of Mg produces how much mass of H₂?

[tex]mass of H_{2} =\frac{12.5 grams of Mg* 2 grams of H_{2}}{24.31 grams of Mg}[/tex]

mass of H₂= 1.03 grams

1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.

Answer:

is your question correct

.

..

.

.

.

or not

Answer:

1. Absolute time, also known as Newtonian time is a time that exists independent of the observer of the time, and therefore, can only be expressed through mathematics

Absolute dating is a dating method that makes use of the radioactive property of matter and is determined through dating of radioactive isotopes present

Absolute time (dating) is found through radioactive dating

2. Radioactive isotopes are atoms that have the property of unstable proton neutron combination or excess energy nucleus. They can be fined as unstable element

3. A stabilized isotope are the decay product atoms of the element which are non radioactive.

4. The half life is the time it takes the original isotope to decay into the decay product

5. To determine the age of a rock, the proportion of the original isotope to the amount of decay product in the rock is compared

6. The isotope used to date organic materials is carbon-14

7. The isotope used to date rocks with comparable age to the Earth is Uranium-238 that has a half life of 4.468 billion years

8. The half life of carbon-14 is only 5,700 years while the age of a dinosaur is between 245 and 66 million years ago, and therefore, carbon is absent in most fossils

9. Uranium-238 is only found in igneous or volcanic rocks and not in metamorphic rocks, therefore, fossils  of dinosaur as well as other fossils that are buried in sedimentary materials, including sand and clay, cannot be determined by Uranium-238

Explanation:

Answer:

may be you mean water= hydrogen + oxygen, this reaction describes that water is made by the combination of hydrogen and oxygen.

Answer:

87059.50558 pa

Explanation:

Dalton's law of partial pressure states that Ptotal=P1 +P2+ P3

417mmHg + 150mmHg +86mmHg =653 mmHg

convert it to Pa, your answer is 87059.50558Pa.

I hope I'm of help to you