Which are correct ???

Which Are Correct ???

Answers

Answer 1

Answer:

last one

Explanation:

endothermic reactions release energy


Related Questions

Solid nickel reacts with aqueous lead (II) nitrate to form solid lead. What is the net ionic equation for this reaction? • Hint: In this reaction, nickel exhibits its most common oxidation state of +2. • Be sure to include the charge for each ion in the net ionic equation. Provide your answer below: (s) + (aq) → *(n)

Answers

Answer:

Pb²⁺(aq) --> Ni²⁺(aq)

Explanation:

The equation of the reaction is given as;

Ni(s) + Pb(NO₃)₂(aq) --> Pb(s) + Ni(NO₃)₂(aq)

In writing the ionic equation, we break the aqueous compound into ions. The solid and liquid compounds are ignored.

We have;

Pb²⁺(aq)  + NO₃²⁻(aq) -->  Ni²⁺(aq)  + NO₃²⁻(aq)

Canceling the spectator ions;

Pb²⁺(aq) --> Ni²⁺(aq)

Answer:

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Explanation:

The complete ionic equation of this reaction is

Ni(s)+Pb2+(aq)+2 NO−3(aq)→Ni2+(aq)+2 NO−3(aq)+Pb(s)

The nitrate ions are spectator ions and can be removed from the equation, giving us

Ni(s)+Pb2+(aq)→Ni2+(aq)+Pb(s)

Question 1 of 7

Which sentence correctly explains the change that occurs when ice melts?
Ice melting is a physical change, and the state of the substance remains the same.
Ice melting is a physical change, and the mass of the substance remains the same.
оо оо
Ice melting is a chemical change, and the state of the substance remains the same.
Ice melting is a chemical change, and the mass of the substance remains the same.

Answers

Answer:

Explanation:B ice melting is a phiyscal change and the mass of the substance remains the same

Answer:

b

Explanation:

Peptides can be separated using an ion‑exchange column based on their isoelectric (pI) values. At which pH values would two different peptides, one with a pI of 5.3 and the other with a pI of 8.5 , bind to a cation‑ and anion‑exchange column? Each peptide may be capable of binding to each column at more than one pH value.

Answers

Answer:

At pH 3.5:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the anion-exchange column.

At pH 6.5:

Peptide A with pI 5.1 will bind to the cation-exchange column, while peptide B with pI 8.5 will bind to the anion-exchange column.

At pH 10.8:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the cation-exchange column.

Explanation:

Ion-exchange column chromatography is used for separating proteins and other molecules in a solution based on differences in net  charge. Negatively charged molecules bind to positively charged solid supports called the anion-exchange column, whereas, positively charged molecules bind to  negatively charged solid supports known as cation-exchange column.

A peptide can acquire a net charge if the pH of the medium is either above or below its isoelectric point,pI. At pH above pI, the peptide acquires a net negative charge and can bind to a positive support. At pH above pI, the peptide acquires a net positive charge and can bind to a negative support. The greater the difference between pH and pI, the tighter the peptide will bind to the column.

At pH 3.5:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the anion-exchange column.

At pH 6.5:

Peptide A with pI 5.1 will bind to the cation-exchange column, while peptide B with pI 8.5 will bind to the anion-exchange column.

At pH 10.8:

Peptide A with pI 5.1 and peptide B with pI 8.5 will both bind to the cation-exchange column.

how many grams of diazine (N2H2) are there in 2.55 mol of the compound

Answers

Answer:

76.5g is present in 2.55mol of diazine

Explanation:

no. of mole equals mass over molar mass

molar mass of diazine equals 30g/mol.. then substitute to get the mass in grams which is 76.5g


Most of Earth's atmosphere is made up of nitrogen gas. Nitrogen can also
exist as a solid, liquid, or plasma. Four samples of nitrogen are each in a
different state but have the same mass. Which statement about the relative
amounts of thermal energy in the samples is true?
O A. The sample of solid has more energy than the sample of gas.
B. The sample of liquid has more energy than the sample of solid.
C. The sample of plasma has less energy than the sample of gas.
D. The sample of liquid has less energy than the sample of solid.

Answers

The sample of the liquid has more energy than the sample of solid. Hence, option B is correct.

What is thermal energy?

Thermal energy refers to the energy contained within a system that is responsible for its temperature.

The particles in the liquid are the same as in the solid but they have more energy. To melt solid energy is required to overcome the attraction between the particles and allow them to pull them apart. The energy is provided when the solid is heated up.

Hence, option B is correct.

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A student is conducting an experiment to see which material, when placed in a closed circuit, will still allow a light bulb to light up. With which material would the student have success?
A.sulfur
B.copper
C.glass
D.wood

Answers

B, because that is what it says

The student would have success in experiment with using copper in a closed circuit as it allows conduction and is a good conductor of electricity.

What is conduction?

Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.

In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .

When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:

1) heat conduction

2) electrical conduction

3)sound conduction

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What is the final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L

Answers

Answer: The final concentration of a solution is 0.350 M

Explanation:

According to the dilution law,

[tex]C_1V_1=C_2V_2[/tex]

where,

[tex]C_1[/tex] = concentration of concentrated acid solution = 12.0 M

[tex]V_1[/tex] = volume of concentrated acid solution = 35.0 ml

[tex]C_2[/tex] = concentration of diluted acid solution= ?

[tex]V_2[/tex] = volume of another acid solution= 1.20 L = 1200 ml

( 1L=1000ml)

Putting in the values:

[tex]12.0\times 35.0=C_2\times 1200[/tex]

[tex]C_2=0.350M[/tex]

The final concentration of a solution prepared by diluting 35.0 mL of 12.0 M HCl to a final volume of 1.20 L is 0.350 M

Unsanitary meat processing, poisonous additives, and false claims about the efficacy of drugs (i.e., "snake oil") resulted in the original Food
and Drugs Act and Meat Inspection Act in 1906.

True or False

Answers

i believe that this will be true

Predict and write the charges and symbols of the monatomic ions formed by the following atoms: bromine rubidium

Answers

Answer: The monoatomic ions formed by bromine and rubidium are [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

Explanation:

When an atom accepts an electron negative charge is created on atom and is called as anion.  When atom loses an electron positive charge is created on atom and is called as cation.

The atomic number of bromine and rubidium is 35 and 37 respectively. So, the number of electrons is equal to 35 and 37 respectively. Bromine will gain one electron and rubidium will lose one electron to attain stable electronic configuration to form [tex]Br^-[/tex] and [tex]Rb^+[/tex] respectively.

[tex]Br:35:1s^22s^22p^63s^23p^64s^23d^{10}4p^5[/tex]

[tex]Br^-:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

[tex]Rb:37:1s^22s^22p^63s^23p^64s^23d^{10}4p^63s^1[/tex]

[tex]Rb^+:36:1s^22s^22p^63s^23p^64s^23d^{10}4p^6[/tex]

10 The rate of the reaction between hemoglobin (Hb)
and carbon monoxide (CO) was studied at 20°C.
The following data were collected with all
concentration units in u mol/L. (A hemoglobin
concentration of 2.21 u mol/L is equal to
2.21 x 10 mol/L.)
[Hblo [CO),
Initial Rate
(u mol/L) (u mol/L) (u mol/Ls)
2.21
1.00
0.619
4.42
1.00
1.24
4.42
3.00
3.71
(a) Determine the orders of this reaction with
respect to Hb and CO.
(b) Determine the rate law.
(c) Calculate the value of the rate constant.
(d) What would be the initial rate for an
experiment with [Hb]o =3.36 u mol/L
[CO] =2.40 4 mol/L?​

Answers

Answer:cookie

Explanation:

7) If the mass of an object is 20 g and its volume is 25 L. What is the density of this object? 1 8) What is the difference between accuracy and precision? Copy and paste a picture of something that accurate but not precise and also something that is precise, but not accurate. 9) What is the formula for percent error?



this is due under 30 mins, please help​

Answers

sorry i have a test and need points love u

Answer:

Accuracy is the closeness of a measured value to the accepted or exact value. The precision of a tool is the smallest unit of measure the tool provides. The smaller the units a tool can measure, the more precise the tool. A measurement can be precise and not be accurate.

Explanation:

Which of the following elements will lose electrons to form an
ion? Check all that apply.
Р
Fe
Pb
Se

Answers

b and c...will lose electron(s) in forming an Ion.

P is an Anion
b..Fe. and c...Pb form Cations (+) by losing electrons.
d. Se is an Anion.

Elements that will loose electron as so that ion can be formed are; Fe and Pb.

Fe ( iron ) and Pb ( Lead)  are both metals and metals will always loose electron so that they can turn to postively charged ion, and this ion is regarded as Cation.

Phosphorus (P) is a non- metal,  it will only gain electron and turn to a negatively charged ions, this ion is regarded as Anion.

Therefore, Metals usually lose electron while non- metals accept the electron.

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Hello I was wondering if anyone knew how to draw the molecular geometry of fentanyl. I already did the Lewis structure.

Answers

Answer:

i dont

Explanation:

Which of the following statements about atomic mass is true? (help asap)
A. It represents the number of protons
B. It is the relative amount of mass of the element
C. It is the whole number used to numerically order the elements
D. It equals the number of electrons when the element is a neutral atom

Answers

Answer:

B

Explanation:

Because the atomic mass is the mass of a single atom of a chemical elements

The following image represents the movement of a tsunami, a giant wave produced by an earthquake at sea. Which type of model is represented in this image?

A: Computer simulation
B: Graph
C: Map
D: Small-scale object

Answers

Answer:

A

Explanation:

It is not c or b, D is not applicable so it must be A

A mixture of 80.0 g of oxygen and 80.0 g of helium has a total
pressure of 0.1800 atm. What is the partial pressure of each gas?

Answers

Answer:

Partial pressure of O₂ =  0.0198 atm

Partial pressure of He = 0.1584 atm

Explanation:

Given data:

Mass of oxygen = 80.0 g

Mass of helium = 80.0 g

Total pressure = 0.1800 atm

Partial pressure of each gas = ?

Solution:

First of all we will calculate the number of moles.

Number of moles of oxygen:

Number of moles = mass/molar mass

Number of moles = 80.0 g/ 32 g/mol

Number of moles = 2.5 mol

Number of moles of helium:

Number of moles = mass/molar mass

Number of moles = 80.0 g/ 4 g/mol

Number of moles = 20 mol

Total number of moles = 20 mol + 2.5 mol = 22.5 mol

Mole fraction of O₂ = 2.5 mol/ 22.5 mol = 0.11

Mole fraction of He = 20 mol / 22.5 mol = 0.88

Partial pressure:

Partial pressure of O₂ =  0.11× 0.1800 atm = 0.0198 atm

Partial pressure of He = 0.88 × 0.1800 atm = 0.1584 atm

What is the relationship between pressure and temperature

Answers

Answer:

The Pressure Temperature Law. This law states that the pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature. With an increase in temperature, the pressure will go up.

Explanation:

As a sample's temperature increases, which two factors also increase?
A. Particle speed
O.B. Particle boiling point
C. Particle kinetic energy
D. Particle size
Help please

Answers

Answer:

speed

energy

Answer:

particle speed and particle energy

Explanation:

i just took the quiz on a p e x

A cyclist traveled 2 miles in 10 minutes. What is the average speed of the cyclist?
Group of answer choices

Answers

Answer:

about 6 min

Explanation:

PLEASE HELP!! I WILL MARK THE 1st ONE BRAINLIEST!

Answers

Answer:

2 3 and 6

Explanation:

What type of compound is disulfur dichloride?
a. organic compound
b. acid (ionic compound)
c. covalent compound
d. ionic compound

Answers

Answer:

Covalent compound

Explanation:

It is formed by covalent bonds, in which the atoms share a pair of valence electrons

substance in which two or more atoms are bonded together.

Answers

molecule(s)

two or more atoms touching means they are connected as molecules which also make up compounds

An ice cube melts in the hot sun. Is this exothermic or endothermic and
why?

Answers

Answer:

Endothermic

Explanation:

In order to melt the ice cube, heat is required, so the process is endothermic. Endothermic reaction In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings by the reaction.

Gustavo and Beatriz are pushing on a door in opposite
directions. If the door does not move, the forces are
The net force in this scenario would be Answer: balanced and zero

Answers

Answer:

Correct

Explanation:

Balanced forces are always zero!

Answer:

Balanced

Zero

Explanation:

The table below shows the average seasonal relative humidity during the summer in four locations:
Relative Humidity
Location Average Seasonal Relative Humidity (%)
A
76
81
с
60
D
98
B
Which location is most likely to experience frequent summertime storms? (3 points)
Location A
Ob
Location B
Oc
Location C
Od
Location D

Answers

Answer:

C

Explanation:

It’s the lowest to create storms

Please help I need a answer to both

Answers

Hi , I’m really sorry because I just have the first question... so here it is :

So it is 0.52 mol .

Have a nice day .

which of these is a cost of using paper grocery bags

Answers

Answer:

15 cents where im from

Explanation:

which of the elements below has a smaller atomic radius. element1: 1s2 2s2 2p4 element2: 1s2 2s2 2p5​

Answers

Answer:

both are same give different number

Which method of heat transfer allows you to fry an egg in a frying pan on the stove?

Answers

Answer:

Conduction

Explanation:

Answer:

Conduction is correct

Explanation:

Pls Help! 100 Points!!!!!
Which of the following correctly compares the radii of F and F−?

A) F has a smaller radius than F− because an additional electron causes greater repulsion in F−.
B) F has a larger radius than F− because an additional electron causes greater repulsion in F.
C) F has a smaller radius than F− because F− has an additional energy shell.
D) F has a larger radius than F− because F has an additional energy shell.

Answers

The answer is C.
Hope this helps:)

F has a smaller radius than F− because F− has an additional energy shell  correctly compares the radii of F and F−. The correct option is C.

Thus, Compared to oxygen, fluorine is a stronger electronegative element. The outermost electrons of fluorine are gripped by the nucleus more tightly than oxygen because fluorine has a high electronegativity.

It takes more energy to remove the outermost electron of fluorine than it does to remove the outermost electron of oxygen. Fluorine has a higher ionization energy than oxygen as a result.

An atom's energy is determined by how much energy it gains or loses as a result of chemical processes that result in electron loss or gain. Exothermic reactions are those in which energy is released, and endothermic reactions are those in which energy is absorbed.

Exothermic reactions produce negative energy, which is why energy is given a negative sign.

Thus,  F has a smaller radius than F− because F− has an additional energy shell   correctly compares the radii of F and F−. The correct option is C.

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