During all chemical reactions, mass, energy and charge are

QUESTION POSTED AT 15/01/2020 - 01:31 AM

Answered by admin AT 15/01/2020 - 01:31 AM

conserved. if its absorbed then there will be no reaction.
Post your answer

Related questions

To create an element, a(n) _______________ reaction must take place. electromagnetic gravitational chemical nuclear

A chemical reaction is the rearrangement of the molecular or ionic structure of an element.
A nuclear reaction is a change in identity or characteristics of an atomic nucleus that is reacted when being hit with an energy particle extremely hard.
I believe it is nuclear reaction.

ANSWERED AT 21/01/2020 - 09:45 AM


QUESTION POSTED AT 21/01/2020 - 09:45 AM

What is the relationship between a mole and Avogadro’s number? A mole is the mass of Avogadro’s number of particles of a substance. A mole is the amount of a compound that has Avogadro’s number of carbon-12 atoms in it. A mole contains Avogadro’s number of particles of a substance. A mole is the amount of any substance that has the same mass as Avogadro’s number of carbon-12 atoms.

Answer: A mole contains Avogadro’s number of particles of a substance.

Explanation:

Avogadro number is defined as the number of particles (atoms or molecules) of present in per mole of that substance. It is denoted by symbol N_A.

According to mole concept, one mole of an atom contains Avogadro's number of particles of that substance.

1mole=N_A=6.022\times 10^{23} mol^{-1}

ANSWERED AT 21/01/2020 - 09:44 AM


QUESTION POSTED AT 21/01/2020 - 09:44 AM

Which best describes ionization energy? energy needed to add an electron to a neutral atom in the gas phase energy needed to add an electron to a neutral atom in the liquid phase energy needed to remove an electron from an atom or ion in the gas phase energy needed to remove an electron from an atom or ion in the liquid phase

Ionization energy is the energy needed to remove an electron from an atom or ion in a gas phase. The atom will become a cation and has an excess of proton, thus it will be positively charged. Ionization energy usually removes the most loosely bound valence electron.

ANSWERED AT 21/01/2020 - 09:38 AM


QUESTION POSTED AT 21/01/2020 - 09:38 AM

Sodium chloride reacts with copper sulfate to produce sodium sulfate and copper chloride This equation represents a A:synthesis reaction. B:decomposition reaction. C:single replacement reaction. D:double replacement reaction.

Answer: Option (D) is the correct answer.

Explanation:

When sodium chloride reacts with copper sulfate to produce sodium sulfate and copper chloride then sodium being more reactive displaces copper from copper sulfate and copper combines with chlorine.

Thus, reactions where two compounds react and cations and anions of both compounds interchange their respective places then this type of reaction is known as double displacement reaction.

For example, NaCl + CuSO_{4} \rightarrow NaSO_{4} + CuCl is a double displacement reaction.

ANSWERED AT 21/01/2020 - 09:12 AM


QUESTION POSTED AT 21/01/2020 - 09:12 AM

According to the equation 2Na + 2H2O mc012-1.jpg 2NaOH+H2, what mass of Na is required to yield 22.4 L of H2 at STP? (The atomic mass of Na is 22.99 u.)

45.78 just took the test so 46.0 round up

ANSWERED AT 21/01/2020 - 09:11 AM


QUESTION POSTED AT 21/01/2020 - 09:11 AM

PLEASE CHECK MY SEMESTER EXAM ANSWERS!!! I HAVE A FLIGHT TO CATCH!! MUST SUBMIT SOON!!! Question 1 (Multiple Choice Worth 2 points) [07.06]What is the major difference between nuclear and chemical reactions? Only chemical reactions release energy. Only chemical reactions release gamma rays. Only nuclear reactions involve the exchange of electrons. I picked: Only nuclear reactions change the identity of an element. ------------------------------------------------------------------ Question 2 (Multiple Choice Worth 2 points) [07.03]When water is added to an Erlenmeyer flask and then sealed, phase equilibrium occurs. Which answer explains the resulting dynamic equilibrium? Rate of evaporation = rate of precipitation I picked: Rate of condensation = rate of evaporation Moles of vapor = moles of liquid Moles of vapor = moles of solid ------------------------------------------------------------------ Question 3 (Multiple Choice Worth 2 points) [05.01]Which phase of matter is made up of particles that are packed closely together, with both a definite shape and a definite volume? Gas Liquid Plasma I picked: Solid --------------------------------------------------------------- Question 4 (Multiple Choice Worth 2 points) [06.02]When sulfuric acid is poured on sugar the volume of sugar expands and the sugar turns black and becomes very hot. Which of the following best describes this reaction? Endothermic I picked: Exothermic Decomposition Synthesis ----------------------------------------------------------------- Question 5 (Multiple Choice Worth 2 points) [07.01]Which of the following is not true of acids? Acids are corrosive. I picked: Acids feel slippery. Acids have a sour taste. Acids have more hydronium ions than hydroxide ions. ---------------------------------------------------------------------- Question 6 (Multiple Choice Worth 2 points) [06.04]According to the collision theory, what is the best explanation for why a higher temperature makes a reaction go faster? There are fewer collisions per minute. It increases the distance between the particles. It decreases the average kinetic energy of the particles. I picked: It increases the average kinetic energy and number of collisions per minute. ---------------------------------------------------------------- Question 7 (Multiple Choice Worth 2 points) [07.02]Which of the following represents pure water? [H3O+] > [OH-] [H3O+] < [OH-] I picked: [H3O+] = [OH-] [H3O+] [OH-] = 14 ---------------------------------------------------------------------------- Question 8 (Multiple Choice Worth 2 points) [07.06]Which of the following types of radiation can penetrate the most deeply into your body? Alpha rays Beta rays I picked: Gamma rays Proton rays ---------------------------------------------------------------- Question 9 (Multiple Choice Worth 2 points) [07.05]In the chemical reaction shown below, which element was oxidized? 2K + Cl2 yields 2KCl I picked: K, because it lost one electron K, because it gained one electron Cl, because it lost one electron Cl, because it gained one electron ---------------------------------------------------------------------- Question 10 (Multiple Choice Worth 2 points) [06.02]On an exothermic potential energy diagram, what is true for the products? The products are at the same energy level as the reactants. I picked: The products are at a lower energy level than the reactants. The products are at a higher energy level than the reactants. The products do not have energy. ----------------------------------------------------------------- Question 11 (Multiple Choice Worth 2 points) [07.02]What is the salt formed in the following neutralization reaction? Mg(OH)2 + HCl yields H2O + MgCl2 Mg(OH)2 HCl H2O I picked: MgCl2

Answer:

Q1 - Only nuclear reactions change the identity of an element, since they work with the element nucleus which is the atom's part that involves the number of protons in it. The protons define what element we are using in the reaction.

Q2- Rate of condensation = rate of evaporation, since water is in liquid form and the two possible transformations that can happen without changing the flask's temperature are condensation and evaporation. There is no solid form involved to cause precipitation and we don't calculate the moles based on the state the molecules are presented like liquid and vapor.

Q3- Solid phase of matter has a definite shape and volume, since the molecules are arranged in a specific way, close to each other and without much movement possibilities.

Q4- Exothermic, since the reaction involves heat liberation, which characterizes exothermic reactions.

Q5 - Acid feel slippery is not a true consideration when talking about acids' properties. This property would be true to bases, which explains the soapy feeling when it degrades fats into soap.

Q6- It increases the average of kinetic energy and number of collisions per minute, because it gives kinetic energy to the molecules involved in the process, making them move faster and collide more to each other.

Q7- [H3O+]=[OH-] , since those are the ions in water molecules. When combined, they form H2O, the pure water form.

Q8- Gamma rays can penetrate your body the deepest, since they are very energized and short-wavenlenghted. These properties make it easier for them to penetrate into your body.

Q9 - K, because it lost one electron due to the ionic bond that is being formed in the product KCl.

Q10- The products are at a lower energy level than the reactants, since energy is lost during the reaction through heat liberation (exothermic reactions liberate heat to the surroundings).

Q11 - MgCl2, since a salt is composed by two inorganic elements.

ANSWERED AT 21/01/2020 - 09:10 AM


QUESTION POSTED AT 21/01/2020 - 09:10 AM

The density (mass/volume) of aluminum is 2.70x10^3 103 kilograms per cubic meter (kg/m3). What is the mass of an aluminum cylinder that has a volume of 1.50 m3?

The definition of density is the mass per volume of the substance. This is an intrinsic property therefore the size (or any external feature) does not change this property.

For aluminum, it is given that it has a density of 2.70 x 10^3 kg/m^3.

The problem states that there is an aluminum substance having a volume of 1.50 m^3

Mass of aluminum = (1.50 m^3)( 2.70 x 10^3 kg/m^3) = 4050 kg 

ANSWERED AT 21/01/2020 - 09:04 AM


QUESTION POSTED AT 21/01/2020 - 09:04 AM

Now consider an excited state hydrogen atom. What is the energy of the electron in the N= 2 level

I get a result of -5.4925 x10^-19 hope this helped 

ANSWERED AT 21/01/2020 - 09:00 AM


QUESTION POSTED AT 21/01/2020 - 09:00 AM

If an object has a volume of 5 mL and a mass of 50 g, what is the density of the object? 0.10 10 40 250

Using the formula density = mass ÷ volume, I got my answer as 10g/cm^3 or 10g/mL

ANSWERED AT 21/01/2020 - 08:55 AM


QUESTION POSTED AT 21/01/2020 - 08:55 AM

Write a balanced chemical equation that expresses the reaction that will occur during this experiment and that will convert hydrogen peroxide (H2O2) to oxygen (O2) gas and liquid water (H2O).

The balanced reaction is: H2O2 -> H2O + (1/2) O2

However, this is a very awkward equation since it has a coefficient in fraction form.

Another way to write this equation is:

2 H2O2 -> 2 H2O + O2

Hope this helps.

ANSWERED AT 21/01/2020 - 08:44 AM


QUESTION POSTED AT 21/01/2020 - 08:44 AM

If 17.8 grams of KOH dissolve in enough water to make a 198-gram solution, what is the concentration in percent by mass?

Solute of solution = 17.8 g

Solvn = 198 g

% = 17.8 / 198

w% = 0.089 x 100 = 8.9%  by mass

hope this helps!

ANSWERED AT 21/01/2020 - 08:30 AM


QUESTION POSTED AT 21/01/2020 - 08:30 AM

Masses in a sculptural composition can be composed using what?

Linear Principles is the answer

ANSWERED AT 21/01/2020 - 08:26 AM


QUESTION POSTED AT 21/01/2020 - 08:26 AM

Noble gases have a full outer energy level and are inactive. These atoms are considered _____. neutral inert an anion a cation

I believe that the answer  .is ( b ) inert 

ANSWERED AT 21/01/2020 - 08:26 AM


QUESTION POSTED AT 21/01/2020 - 08:26 AM

The atomic mass of an element whose atoms consist of six protons, seven neutrons, and six electrons is _____. 6 12 13 19

Answer: Option (c) is the correct answer.

Explanation:

Atomic mass is the sum of total number of protons and neutrons present in an atom. Whereas atomic number is the total number of protons present in an atom.

And when an atom is neutral then the number of protons equal the number of electrons.

So,     atomic mass = no. of protons + no. of neutrons

                                = 6 + 7

                                = 13

Thus, we can conclude that the atomic mass of an element whose atoms consist of six protons, seven neutrons, and six electrons is 13.

ANSWERED AT 21/01/2020 - 08:08 AM


QUESTION POSTED AT 21/01/2020 - 08:08 AM

Tijuan mixed a solid and a liquid together in a beaker. He determined that a chemical change occurred. If his conclusion is correct, which substances could he have been observing and why? ice mixed into warm oil, because the change of state that occurred when the ice melted cannot be reversed baking soda mixed into vinegar, because the production of bubbles indicates that a new substance formed sugar mixed into hot water, because the disappearance of solid indicates that the chemical identity of the sugar changed sand mixed into water, because when sand was added the mass of the beaker increased

Answer: second option, baking soda mixed into vinegar, because the production of bubbles indicates that a new substance formed.

Explanation:

1) Indeed the evolution of bubbles when two different substances are mixed together is a good indication that a new substance has been formed. That is because the bubbles are a gas product of the chemical reaction between the reactants.

2) Since, baking soda (NaHCO₃) and vinegar (acetic acid, CH₃COOH) are aqueous solutions, you do not have bubles evolving when they are not mixed. Once, they are mixed, the acetate ion (CH₃COO⁻) will combine with the sodium ion (Na⁺) forming sodium acetate (CH₃COONa) and CO₂ which is the gas (bubbles).

3) Regarding the other options:

i) ice mixed into warm oil: the melting of the ice is just a change of phase, and that is all what you can tell about this interaction. Certainly not a chemical change. In fact, that change can be easily reversed by cooling the mixture.

ii) sugar mixed into hot water: the disappearance of the solid sugar does not indicate that the chemical identity of the sugar changed; it just dissolved; a solution was formed. If you heat the solution, the water will evaporate and you will be able to see the sugar crystals.

4) sand mixed into water: this is a classical example of a heterogeneous mixture, where both substances remain clearly being the same. The addition of mass is not an indicator of a reaction. Mass conservation is a principle that is valid for both physical and chemical changes.

ANSWERED AT 21/01/2020 - 08:00 AM


QUESTION POSTED AT 21/01/2020 - 08:00 AM

Which statement best describes what happens during a chemical change? Both the identity and the properties of a substance change. Some properties of a substance change, but its identity remains the same. The chemical properties of a substance change, but its physical properties remain the same. The physical properties of a substance change, but its chemical properties remain the same.

I think the best answer that will describe chemical change is the first option. During a chemical change, both the identity and the properties of a substance change because new substances are being formed by a chemical reaction. An example is rusting of steel

ANSWERED AT 21/01/2020 - 08:00 AM


QUESTION POSTED AT 21/01/2020 - 08:00 AM

12. Which of the following statements is true about a nickel-cadmium dry cell? (Points : 3) The cathode reaction is Cd + 2OH Cd(OH)2 + 2e. The cathode reaction is Cd + NiO2 + 2H2O Cd(OH)2 + Ni(OH)2. The cathode reaction is NiO2+ H2O + 2e Ni(OH)2 + 2OH. The anode reaction is NiO2 + H2O + 2e Ni(OH)2 + 2OH.

The correct answer among the options given is the first one. The cathode reaction for a nickel-cadmium dry cell is Cd + 2OH Cd(OH)2 + 2e. It should be remembered that at the cathode reduction always happen and reduction is the gain of electrons. As we can see from the half reaction, there is a gain of 2 electrons.

ANSWERED AT 21/01/2020 - 07:59 AM


QUESTION POSTED AT 21/01/2020 - 07:59 AM

If a system is left to change spontaneously, in what state will it end? A. the state with lowest possible energy and maximum disorder B. the state with the maximum disorder and the highest energy C. the same state in which it began D. the state with the lowest possible energy consistent with the state of maximum disorder

Answer:  the state with the lowest possible energy consistent with the state of maximum disorder

Explanation:  Spontaneous means that the system does not require any external force to produce nay kind of energy or work.

Thus when a system is left to change spontaneously that is on its own accord, the state with the lowest possible energy consistent with the state of maximum disorder will result.

As lowest possible energy state is the most stable state and maximum disorder means the maximum entropy.

ANSWERED AT 21/01/2020 - 07:49 AM


QUESTION POSTED AT 21/01/2020 - 07:49 AM

If the total mass of the products of a reaction is less than the mass of the reactants, what must be true? A nuclear reaction has taken place. A chemical reaction has taken place. Nuclear fusion has occurred. Nuclear fission has occurred.

The correct answer is nuclear fission because nuclear fission occurs when one HEAVY atomic nucleus splits into two SMALL nuclei

the guy above does not know this :/ :? :x XD

ANSWERED AT 21/01/2020 - 07:44 AM


QUESTION POSTED AT 21/01/2020 - 07:44 AM

An over-the-counter multi-vitamin has 250.0 mg tablets that are 40 % Vitamin B6 by mass. If you take 2 tablets, what mass of Vitamin B6 have you ingested?

This is more of a math problem than a chemistry problem. We know that each tablet is 250 mg. The problem specified that there are 2 tablets making the final weight to be 500 mg. We can also view this as individual tablets. The Vitamin B6 in one tablet is 250. (0.4) = 100 mg. The other tablet would also have 100 mg of Vitamin B6. Two tablets will then have 200 mg of Vitamin B6. Also, 500 (0.4) is also 200 mg. 

ANSWERED AT 21/01/2020 - 07:42 AM


QUESTION POSTED AT 21/01/2020 - 07:42 AM

Chemical equation for liquid ethyltoluene

The answer is Toluene.

ANSWERED AT 21/01/2020 - 07:32 AM


QUESTION POSTED AT 21/01/2020 - 07:32 AM

What is the limiting reactant in the reaction 3CuCl2+2Al->3Cu+2AlCl3 3Cucl2-2.50g (Measured mass),134.45g/mol 2Al-.5g(measured mass), 26.98g/mol

The balanced chemical reaction:

3CuCl2+2Al->3Cu+2AlCl3

We are given the amount of the reactant to be used for this reaction. These values will be the starting point of the calculations.

2.50 g CuCl2 ( 1 mol 
CuCl2 / 134.45 g CuCl2) = 0.019 mol CuCl2
5 g Al ( 1 mol Al / 26.98 g Al ) = 0.185 mol Al

The mole ratio of the reactants is 3:2. In every 3 moles of CuCl2, 2 mol of Al is required. Therefore, the limiting reactant is CuCl2.

ANSWERED AT 21/01/2020 - 07:32 AM


QUESTION POSTED AT 21/01/2020 - 07:32 AM

The molecular mass of octane is 114.22 g/mol. What is the mass of 22.05 mol of octane? 5.180 g 22.05 g 114.22 g 2,518 g

Answer:

The mass of 22.05 mol of octane is 2,518 g.

Explanation:

Molar mass of octane = 114.22 g/mol

Mass of 1 mole of octane is 112.22 g/mol.

Mass of compound:

Moles of compound  × Molar mass of compound

Mass of 22.05 moles of octane is:

22.05 mol\times 114.22 g/mol=2,518.55 g

The closest answer from the given options is 2,518 g.

ANSWERED AT 21/01/2020 - 07:24 AM


QUESTION POSTED AT 21/01/2020 - 07:24 AM

What is the mass, in grams, of a sample of 7.83 x 10^24 atoms of helium (He)? Show your work or explain thr steps that you used to determine your answer.

An important information, specifically a constant, we need to know is the Avogadro's number. Avogadro's number is equal to 6.022*10^23 mol^-1. 
This is the constant we use to convert atoms to moles. So we need to divide 7.83 x 10^24 atoms with the Avogadro's number to get the number of moles. That will be equal to 13 moles of He. Then to convert  moles to grams we need the molar mass of Helium (4 grams/mole). We then multiply the number of moles with the molar mass of Helium. We would have 52 grams of Helium. 

ANSWERED AT 21/01/2020 - 07:22 AM


QUESTION POSTED AT 21/01/2020 - 07:22 AM

Which of the following best represents potential energy being converted to kinetic energy? A) in the chemical energy in a battery is used to power a cell phone B) The movement of wind turns a windmill that generates electricity C) A man petals a bicycle to ride across town D) I want to kick the soccer ball in scores a goal

The best correct answer is option D. Kicking a soccer ball to the goal represents potential energy being converted to kinetic energy. When the ball is still on the ground, an energy is being stored in the ball called potential. However, as soon as the ball is kicked the potential energy stored is now being converted to another form of energy associated with motion called the kinetic energy.

ANSWERED AT 21/01/2020 - 07:09 AM


QUESTION POSTED AT 21/01/2020 - 07:09 AM