heating curve shows temperature verses energy gain. Which parts of the curve represent a gain in potential energy?
100
Temperature (°C)
0
Increasing Energy

Answer:

Which scientist developed the first model of the atom that showed the structure of the inside of an atom

Ernest Rutherford

Explanation:

First you must calculate the number of moles in this solution, by rearranging the equation. No. Moles (mol) = Molarity (M) x Volume (L) = 0.5 x 2. = 1 mol.

For NaCl, the molar mass is 58.44 g/mol. Now we can use the rearranged equation. Mass (g) = No. Moles (mol) x Molar Mass (g/mol) = 1 x 58.44. = 58.44 g.

Answer:

Number of moles : Mass (g) ÷ relative atomic mass

Answer:

A mixture of sulfuric acid and nitric acid will produce small quantities of the nitronium ion (NO2 ): The nitronium ion has a central nitrogen atom with a positive charge double bonded to two oxygen atoms on both sides. Each oxygen atom carries two lone pairs of electrons. Does the nitronium ion have any significant resonance structures?

Explanation:

The structure of nitronium ion is shown below:

Any molecule to exhibit resonance, it should have alternating double bonds.

Resonance is the phenomenon in which the structure of a molecule can be represented in two or more forms and each form is called canonical form.

The canonical forms do not differ in the position of atoms and they differ only in the position of double bonds.

For the given molecule, there are no alternating double bonds.

Hence, nitronium ion does not exhibit any significant resonance structures.

Answer:

I think the answer is A

Explanation:

the temperature of solids , liquids and gases can be easily measured

Answer:

true

Explanation:

because an organism have many roles in food web

3

And then for Fe it should be 4 and for the products it should be 2!!

Answer: photosynthesis

Explanation:

the number of nitrogen atoms in the compound is two

Answer:

something that can be maintained over a period of time

Answer:

a balance between meeting today's needs.......

Explanation:

Answer:

the scientific study of the relations between heat and other forms of energy

Answer:

pa helpppp

Explanation:

pleseee need answerrrr

The correct relations for exothermic and endothermic reactions from the given relations is  H Products > H Reactants in exothermic reactions. Hence, Option (D) is Correct.

In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change ΔH⚬ is negative." Exothermic reactions usually release heat.

Therefore, The correct relations for exothermic and endothermic reactions from the given relations is  H Products > H Reactants in exothermic reactions. Hence, Option (D) is Correct.

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Answer:

Both reactions are acid-base reactions

Explanation:

An acid base reaction is a reaction that occurs between an acid and a base. This reaction often leads to the formation of a salt in the process. The nature of the salt depends on the type of acid and base that reacted in the process.

Both HNO3 and H2SO4 are strong acids. However, ammonia is a weak base. The acid base reaction between ammonia and these strong acids is shown below;

HNO3(aq) + NH3(aq) ------>NH4NO3(aq)

H2SO4(aq) + 2NH3(aq) ----> (NH4)2SO4(aq)

Answer:

2.37 (w/w)% of NH3 in the fertilizer

Explanation:

The HCl reacts with NH3 as follows:

HCl + NH3 ⇄ NH4Cl

To solve this question we must find the  moles of HCl used in the titration = Moles NH3. With its molar mass we can find mass of NH3 and using the dilutions we can find weight percent as follows:

Moles HCl = Moles NH3

32.37mL = 0.03237L * (0.1077mol/L) =

Mass NH3 in the dilution -Molar mass: 17.031g/mol-

0.003486moles NH3 * (17.031g/mol) = 0.05937g NH3

Mass NH3 in the sample:

0.05937g NH3 * (79.733g + 24.803g) / 10.560g =

0.588g NH3

Weight percent:

0.588g NH3 / 24.803g * 100 =

Answer: The given electronic configuration is long hand notation.

Explanation:

Long-hand notation of representing electronic configuration is defined as the arrangement of total number of electrons that are present in an element.

Noble-gas notation of representing electronic configuration is defined as the arrangement of valence electrons in the element. The core electrons are represented as the previous noble gas of the element that is considered.

The given electronic configuration of potassium (K):  

The above configuration has all the electrons that are contained in the nucleus of an element. Thus, this configuration is a long-hand notation.

From the question given above, the following data were obtained:

Oxygen = 45.2 Kg

Carbon = 12.6 Kg

Hydrogen = 7 Kg

Nitrogen = 2 Kg

Calcium = 1.3 Kg

Phosphorus = 0.78 Kg

Potassium = 0.25 Kg

Sulphur = 0.18 Kg

Others = 0.60 Kg

Total = 70 Kg

We can obtain the fraction of potassium of the mass of the body as follow:

Potassium = 0.25 Kg

Total = 70 Kg

Fraction of potassium = mass of potassium / Total

Fraction of potassium = 0.25 / 70

Therefore, the fraction of potassium in the body is 1/280

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Answer:

the characteristics of ionic compounds are :

1.They form crystals.

2.They are hard and brittle.

Answer:

they form crystals.

they have high melting and boiling points.

they are hard and brittle.

they are good insulators.

when dissolve in water...they dissociate Into ions.

Answer:

C. 2.70 g/mL

Explanation:

Density is the ratio between the mass of a substance and the volume it occupies. Based on Archimedes' volume, the displaced volume of the aluminium is the volume it occupies. To solve this question we must find the difference in volume between initial volume of water = 30mL and final volume of water + aluminium = 39.26mL. This difference is the volume of the aluminium. With its mass we can find density:

39.26mL - 30mL = 9.26mL

Density = 25.00g / 9.26mL =

2.70g/mL

Right answer is:

Answer:

The given molecules are:

CH2Br2

CH3NH2

LiF

C3H8

CF4.

Which compound consists of the hydrogen bond as the strongest intermolecular force.

Explanation:

The hydrogen bond is the electrostatic force of attraction that exists between the covalently bonded H-atom of one molecule and a high electronegative atom (N, O, F) of another molecule.

For example, H-bonding in water is represented below:

Among the given molecules,

CH2Br2 does not have H-bond because there is no either N or O or F atom in it.

In LiF also there is no H-atom and no hydrogen bond.

C3H8 also does not have H-bond in it.

CF4 also does not have H-atom or hydrogen bond in it.

The answer is CH3NH2(methylamine).

It has an intermolecular hydrogen bond in it as shown in the attachment.

The dashed line represents the H-bond.

Answer:

[tex]1 {s}^{2} 2 {s}^{2} 2 {p}^{4} [/tex]

OR

[tex]2 : 6[/tex]

Answer:

If we look at the ground state (electrons in the energetically lowest available orbital) of oxygen, the electron configuration is [tex]1s^{2} 2s^{2} 2p^{4}[/tex] . If the element were to become excited, the electron could occupy an infinite number of orbitals. However, in most texts, the example will be the next available one. So for oxygen, it might look like this:  [tex]1s^{2} 2s^{2} 2p^{3}3s^{1}[/tex]  - where the valence electron now occupies the 3s orbital in an excited (i.e. not ground) state.

So, the electron configuration of oxygen in its excited state​ is [tex]1s^{2} 2s^{2} 2p^{3}3s^{1}[/tex].

Answer:

equal to zero is the right answer

Answer:

CuCl2 (aq) + 2 KOH (aq) → Cu(OH)2 (s) + 2 KCl (aq)

Explanation:

I did it.

Answer:

CuCl2 + 2KOH------------------>Cu(OH)2 + 2KCl

Explanation:

this is the right solution of equation

Answer:

Well, they are very durable unlike other packaging food materials, they can be recycled. But, the internet says allumninum cans are much better. and it could be better because you can keep the canned milk cool (cold) for a long lasting time. (keep it in the fridge if you want it to stay cold even longer)

Answer:

For (a): The balanced net ionic equation is [tex]2Ag^{+}(aq)+S^{2-}(aq)\rightarrow Ag_2S(s)[/tex] and the sum of coefficients is 4

For (b): The balanced net ionic equation is [tex]Pb^{2+}(aq)+2Cl^{-}(aq)\rightarrow PbCl_2(s)[/tex] and the sum of coefficients is 4

For (c): The balanced net ionic equation is [tex]Ca^{2+}(aq)+CO_3^{2-}(aq)\rightarrow CaCO_3(s)[/tex] and the sum of coefficients is

For (d): The balanced net ionic equation is [tex]Ba^{2+}(aq)+2OH^{-}(aq)\rightarrow Ba(OH)_2(s)[/tex] and the sum of coefficients is 4

For (e): The balanced net ionic equation is [tex]Ag^{+}(aq)+Cl^{-}(aq)\rightarrow AgCl(s)[/tex] and the sum of coefficients is 3

Explanation:

Net ionic equation is defined as the equations in which spectator ions are not included.

Spectator ions are the ones that are present equally on the reactant and product sides. They do not participate in the reaction.

The balanced molecular equation is:

[tex]Na_2S(aq)+2AgNO_3(aq)\rightarrow 2NaNO_3(aq)+Ag_2S(s)[/tex]

The complete ionic equation follows:

[tex]2Na^{+}(aq)+S^{2-}(aq)+2Ag^+(aq)+2NO_3^{-}(aq)\rightarrow 2Na^+(aq)+2NO_3^-(aq)+Ag_2S(s)[/tex]

As sodium and nitrate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

[tex]2Ag^{+}(aq)+S^{2-}(aq)\rightarrow Ag_2S(s)[/tex]

Sum of the coefficients = [2 + 1 + 1] = 4

The balanced molecular equation is:

[tex]2NaCl(aq)+Pb(NO_3)_2(aq)\rightarrow 2NaNO_3(aq)+PbCl_2(s)[/tex]

The complete ionic equation follows:

[tex]2Na^{+}(aq)+2Cl^{-}(aq)+Pb^{2+}(aq)+2NO_3^{-}(aq)\rightarrow 2Na^+(aq)+2NO_3^-(aq)+PbCl_2(s)[/tex]

As sodium and nitrate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

[tex]Pb^{2+}(aq)+2Cl^{-}(aq)\rightarrow PbCl_2(s)[/tex]

Sum of the coefficients = [2 + 1 + 1] = 4

The balanced molecular equation is:

[tex]K_2CO_3(aq)+Ca(NO_3)_2(aq)\rightarrow 2KNO_3(aq)+CaCO_3(s)[/tex]

The complete ionic equation follows:

[tex]2K^{+}(aq)+CO_3^{2-}(aq)+Ca^{2+}(aq)+2NO_3^{-}(aq)\rightarrow 2K^+(aq)+2NO_3^-(aq)+CaCO_3(s)[/tex]

As potassium and nitrate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

[tex]Ca^{2+}(aq)+CO_3^{2-}(aq)\rightarrow CaCO_3(s)[/tex]

Sum of the coefficients = [1 + 1 + 1] = 3

The balanced molecular equation is:

[tex]2NaOH(aq)+Ba(NO_3)_2(aq)\rightarrow 2NaNO_3(aq)+Ba(OH)_2(s)[/tex]

The complete ionic equation follows:

[tex]2Na^{+}(aq)+2OH^{-}(aq)+Ba^{2+}(aq)+2NO_3^{-}(aq)\rightarrow 2Na^+(aq)+2NO_3^-(aq)+Ba(OH)_2(s)[/tex]

As sodium and nitrate ions are present on both sides of the reaction. Thus, they are considered spectator ions

The net ionic equation follows:

[tex]Ba^{2+}(aq)+2OH^{-}(aq)\rightarrow Ba(OH)_2(s)[/tex]

Sum of the coefficients = [2 + 1 + 1] = 4

The balanced molecular equation is:

[tex]NaCl(aq)+AgNO_3(aq)\rightarrow NaNO_3(aq)+AgCl(s)[/tex]

The complete ionic equation follows:

[tex]Na^{+}(aq)+Cl^{-}(aq)+Ag^{+}(aq)+NO_3^{-}(aq)\rightarrow Na^+(aq)+NO_3^-(aq)+AgCl(s)[/tex]

As sodium and nitrate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

[tex]Ag^{+}(aq)+Cl^{-}(aq)\rightarrow AgCl(s)[/tex]

Sum of the coefficients = [1 + 1 + 1] = 3

[tex]CuCl_2+2NaNO_3 \rightarrow Cu(NO_3)_2 + 2NaCl[/tex]

Answer:

The student is now told that the four solids, in no particular order, are barium chloride (BaCl2), sugar (C6H12O6), butanoic acid (C3H7COOH), and sodium bromide (NaBr). Assuming that conductivity is correlated to the number of ions in solution, rank the four substances based on how well a 0.20 M solution in water will conduct electricity. Rank from most conductive to least conductive.

Explanation:

The given substances are:

barium chloride(BaCl2),

glucose(C6H12O6),

butanoic acid (C3H7COOH) which is a weak acid,

sodium bromide (NaBr).

The conductivity of a solution is proportional to the number of ions present in a particular solution.

1mol. of BaCl2 in water produces a total three mol. of ions.

[tex]BaCl_2 (aq) -> Ba^2^+(aq) + 2Cl^-(aq)[/tex]

Gluocse is a covalent compound and it does not dissociate into ions in water.

So, it does not conduct electricity.

Butanoic acid is a weak acid. But due to the release of H+ ions it can conduct a very less amount of electricity.

NaBr is an ionic compound and in 1mol. of NaBr in water gives two mol. of ions.

NaBr (aq)  -> Na+ (aq)  + Br- (aq)

Hence, the order of conductivity among the given substances in aqueous solution is:

BaCl2 > NaBr > butanoic acid > glucose

Answer:

It determines how difficult it is to start the reaction.

Explanation:

Answer:

a. NADH and FADH₂ donate electrons to the electron transport chain

b. Molecular oxygen, O₂, is the final electron acceptor

c. The final products of the electron transport chain and oxidative phosphorylation are as follows: NAD+, FAD+, H₂O, and ATP

Explanation:

The citric cycle oxidize acetylCoA molecules to carbon dioxide and in the process produce the reduced coenzyme NADH and FADH₂. These reduced coenzymes then are able to donate their electrons to various complexes in the electron transport chain. The flow of these electrons through the electron transport chain is coupled to proton pumping out of the mitochondrial matrix into the intermembrane space. Ultimately, the energy of the proton motive force is used to drive synthesis of ATP from ADP and inorganic phospahte and the electrons are accepted by molecular oxygen to produce water. This process is known as oxidative phosphorylation.

Therefore, the answers to the given questions a, b and c are as follows:

a. NADH and FADH₂ donate electrons to the electron transport chain

b. Molecular oxygen, O₂, is the final electron acceptor

c. The final products of the electron transport chain and oxidative phosphorylation are as follows: NAD+, FAD+, H₂O, and ATP

Answer:

It produces free energy.

Explanation:

Photosynthesis is a process which is used by the plant for producing energy in the form of ATP. This energy is used by the plants in different activities which enables the plant to grow and develop successfully. There are some factors which causes change in the rate of photosynthesis means the production of energy for the plant body. If the environmental factors are suitable, more energy is produced through the process of photosynthesis.

Answer:

Ketones and ketoacids are alternative fuels for the body that are made when glucose is in short supply. They are made in the liver from the breakdown of fats. Ketones are formed when there is not enough sugar or glucose to supply the body's fuel needs. This occurs overnight, and during dieting or fasting.

Explanation: