Which statement is true?

A. In an exothermic reaction, the energy of the products is the same as the energy of the reactants.

B. In an endothermic reaction, the energy of the products is the same as the energy of the reactants.

C. In an endothermic reaction, the energy of the products is greater than the energy of the reactants.

D. In an exothermic reaction, the energy of the products is greater than the energy of the reactants.

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:

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:

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:

two atoms

Explanation:

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:

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

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:

C. KMnO4/H+

Explanation:

Oxidizing agent is a substance that has the ability to accept electrons from other substances.

Answer:

0.06 liter

Explanation:

First, let us look at the equation of the first reaction:

2HCl + Mg ----> MgCl2 + H2

2 moles of HCl requires 1 mole of Mg for complete reaction.

Mole of HCl available = molarity x volume

                                    0.2 x 50/1000 = 0.1 mole

Mole of Mg available = mass/molar mass

                                    0.6/24.3 = 0.02 mole.

Thus, HCl is in excess by 0.1 mole.

Now, let us look at the second reaction:

HCl + NaOH ----> NaCl + H2O

mole ratio of HCl to NaOH is 1:1

Remember that 0.1 mole HCl is left from the first reaction. Thus, 0.1 mole of the alkaline would also be needed.

Hence, volume of NaOH needed = mole/molarity

                        0.1/1.67 = 0.06 dm3

The volume of alkaline needed would, therefore, be 0.06 liter.

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:

174.259 g/mol

Explanation:

The molecular weight of potassium (K2so4) is 174.259 g/mol .

Hope it is helpful to you

Answer:

beryllium is the answer.

I hope this will help you

The covalent bond with the greatest polarity would form in this atom pair: B. S-O.

Ionic character refers to a percentage of difference between the electronegativity (polarity) of two (2) atoms that are bonded covalently.

Hence, ionic character is directly proportional to the difference between the electronegativity (polarity) of two (2) atoms that forms a covalent bond.

Furthermore, bonded atoms of chemical element that are having the greatest difference in electronegativity usually forms covalent bonds with the greatest polarity.

The electronegativity of some of the chemical element are:

By observation, the difference between the electronegativity (polarity) of Sulfur (S) and Oxygen (0) would form a covalent bond with the greatest polarity.

                       [tex]S-O=3.5-2.58=0.92[/tex]

Read more: https://brainly.com/question/18214726

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:

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

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:

C

Explanation:

∂S represents change in entropy.

Answer:

False

Explanation:

sea floor spreading is not consistent at all mid ocean ridges.

Answer:

is your question correct

.

..

.

.

.

or not

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:

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

Answer:

c hierro

no se la otra sorry

Answer:

a. H2O: dihydrogen monoxide

b. PCl5: Phosphorus pentachloride

c. SiF4: Silicon tetrafluoride

d. N20: dinitrogen oxide