Is it true or false???????

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.

Answer:

yeasts, moulds, bread, beer, wine, ...

Explanation:

Answer: Therefore, the volume of a 0.155 M potassium hydroxide solution  is 56.0 ml

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

According to the neutralization law,

[tex]n_1M_1V_1=n_2M_2V_2[/tex]

where,

[tex]M_1[/tex] = molarity of [tex]HBr[/tex] solution = 0.338 M

[tex]V_1[/tex] = volume of [tex]HBr[/tex] solution = 25.7 ml

[tex]M_2[/tex] = molarity of [tex]KOH[/tex] solution = 0.155 M

[tex]V_2[/tex] = volume of [tex]KOH[/tex] solution = ?

[tex]n_1[/tex] = valency of [tex]HBr[/tex] = 1

[tex]n_2[/tex] = valency of [tex]KOH[/tex] = 1

[tex]1\times 0.338\times 25.7=1\times 0.155\times V_2[/tex]

[tex]V_2=56.0ml[/tex]

Therefore, the volume of a 0.155 M potassium hydroxide solution  is 56.0 ml

There are total three laws of newtons, first law of newtons, second law of newton and third law of newton. Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.

According to Newton's Second Law of Motion, acceleration (gaining speed) occurs when a force acts on a mass (object). Riding a bicycle is a great example of this rule of motion in action. The mass is represented by your bicycle. The force is generated by your leg muscles pulling on the pedals of your bicycle.

The ball remains balanced on the tee due to the balanced forces of gravity downhill and upward. Force equals mass multiplied by acceleration (f=ma). When a golf club is subjected to an imbalanced force, its velocity changes.

Therefore, when a golf club is subjected to an imbalanced force, its velocity changes, which is according to newton’s second law.

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Answer:

X represents London dispersion forces, and Y represents dipole-dipole forces.

Explanation:

Answer:

i dont

Explanation:

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

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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Answer:

The maximum possible yield strength for a single crystal is 70 MPa.

Explanation:

To find the maximum possible yield strength for a single crystal we need to use the following equation:

[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}}[/tex]

Where:

[tex]m_{max}[/tex] is the maximum value for Schmid factor

[tex]\tau_{CRSS}[/tex] is the critical resolved shear stress = 35 MPa

[tex] \sigma_{y}[/tex] is the yield strength =?    

The Schmid factor is given by:

[tex]m = cos(\phi)cos(\lambda)[/tex]

And its maximum value is obtained when λ = 45° and Φ = 45°, so:

[tex] m = cos(45)cos(45) = 0.5 [/tex]

Finally, the maximum possible yield strength is:

[tex]\sigma_{y} = \frac{\tau_{CRSS}}{m_{max}} = \frac{35 MPa}{0.5} = 70 MPa[/tex]

Therefore, the maximum possible yield strength for a single crystal is 70 MPa.

I hope it helps you!                                                                                  

Answer:

atomic number of 12 is MG

Explanation:

Magnesium

Answer:

boron is the right answer I have studied

Answer:

The molarity is 6.0 M.

Explanation:

The concentration of a solution is the amount of solute present in a given amount  of solvent, or a given amount of solution.

In this problem, we are asked to convert percent by mass to molarity, which are two different concentration units.

The percent by mass is the ratio of the mass of a solute to the mass of the solution, multiplied by 100 percent. On the other hand, molarity (M) is defined as the number of moles of solute per liter of solution.

If we have 17.15 percent chloride ion, that means that we have 17.15 grams of chloride ion in 100 grams of solution. The density provided is the density of the solution, so we calculate how many mL correspond to 100 grams of solution:

1.23 g ----------- 1 mL

100 g ------------ x= 81.3 mL

Therefore, 17.5 grams of chloride ion are contained in 81.3 mL. Now we need to convert these grams into moles.

The atomic mass of chlorine is 35.5 g/mol:

35.5 g --------------- 1 mol

17.5 g --------------- x= 0. 49 mol

This 0.49 moles are contained in 81.13 mL, the definition of molarity says that this moles are contained in a liter (or what is the same, 1000 mL):

81.3 mL --------------- 0.49 mol

1000 mL ------------- x= 6.0 M

The molarity of the chloride ion will be 6.0 M.

Answer:

your answer should be B.273 K

Explanation:

Answer:

6 atoms

Explanation:

Answer:

False did the test on egde

Answer:

Q = 7.7 KJ

Explanation:

The complete question carries the following data:

Specific Heat Capacity of Liquid State = C(l) = 1.45 J/mol.°C

Specific Heat Capacity of Gaseous State = C(g) = 0.65 J/mol.°C

Boiling Temperature = Tb = 88.5°C

Heat of Vaporization = ΔH(vap) = 1.23 KJ/mol

Now, first we calculate the heat required (Q₁) to raise he temperature to boiling point:

Q₁ = n*C(l)*ΔT₁

where,

n = no. of moles = 5.31 mol

ΔT₁ = Temperature difference from 40°C to Tb = 88.5°C - 40°C = 48.5°C

Therefore,

Q₁ = (5.31 mol)(1.45 J/mol.°C)(48.5°C)

Q₁ = 373.4 J = 0.37 KJ

Now, we calculate the heat required (Q₂) to change its phase:

Q₂ = nΔH(vap)

Q₂ = (5.31 mol)(1.23 KJ/mol)

Q₂ = 6.53 KJ

Now, we calculate the heat required (Q₃) to raise he temperature to boiling point:

Q₃ = n*C(g)*ΔT₃

where,

n = no. of moles = 5.31 mol

ΔT₃ = Temperature difference from Tb to 113°C = 113°C - 88.5°C = 24.5°C

Therefore,

Q₃ = (5.31 mol)(0.65 J/mol.°C)(24.5°C)

Q₃ = 84.5 J = 0.08 KJ

So, the total heat required to convert 5.31 mol of this pure substance from a liquid at 40°C to a gas at 113°C is:

Q = Q₁ + Q₂ + Q₃

Q = 0.37 KJ + 6.53 KJ + 0.08 KJ

Q = 7.7 KJ

The total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.

The given parameters;

The total heat required to convert the pure substance from liquid to gas at the given temperature is calculated as follows;

[tex]Q = nc_l \Delta \theta + nc_g \Delta \theta \\\\ \Delta \theta = (113 - 40) = 73^0 C \\\\Q = (5.31 \ mol \times 1.45 \frac{J}{mol .\ ^0C} \times 73\ ^0C) + (5.31 \ mol \times 0.65 \frac{J}{mol .\ ^0C} \times 73 \ ^0C)\\\\Q = 814 \ J[/tex]

Thus, the total heat required to convert the pure substance from liquid to gas at the given temperature is 814 J.

"Your question is not complete, it seems to be missing the following information;"

How much heat would be required to convert 5.31 mol of a pure substance from a liquid at 40.0°C to a gas at 113.0°C? (molar heat capacity of liquid, C(l) is 1.45 J/mol.⁰C and molar heat capacity of gas, C(g) is 0.65 J/mol.⁰C).

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Answer:

Chemical

Explanation:

Cause it is

Answer: choice 2

Explanation:

Answer:

last one

Explanation:

endothermic reactions release energy

Answer:

potassium

Explanation:

they are in group a

Answer:

An increase on temperature.

Explanation:

Answer: adding a catalyst or increasing temperature

Explanation:

Explanation:

i dont understand dont you already have the equation?

The net ionic equation for the acid-base reaction PH[tex]_3[/tex](aq) + HCl(aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]Cl(aq) is PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ .

Chemical reaction equations can be written in a variety of ways. Unbalanced chemical equations, which identify the species involved, balanced chemical equations, which identify the number and type of species, molecular equations, that also express compounds as molecules rather than component ions, and net ionic equations, which only address the species which contribute to a reaction, are some of the most popular.

A chemical equation for just a process known as the net ionic equation only includes the species that are really involved in the reaction.

PH[tex]_3[/tex](aq) + HCl(aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]Cl(aq)

PH[tex]_3[/tex](aq) + H⁺ (aq)  + Cl⁻ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ (aq)  + Cl⁻ (aq)

PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺

Therefore,  the net ionic equation for the acid-base reaction is PH[tex]_3[/tex](aq) + H⁺ (aq) [tex]\rightarrow[/tex] PH[tex]_4[/tex]⁺ .

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Answer:

how do I send it to you coz I don't know how to draw in brainly

Answer:

V = 10.12 mL

Explanation:

Given that,

Density, d = 0.79 g/mL

Mass, m = 8 g

We need to find the volume of the object. Density is equal to the mass per unit volume. It can be given by :

[tex]d=\dfrac{m}{V}[/tex]

Where V is the volume of the object

[tex]V=\dfrac{m}{d}\\\\=\dfrac{8\ g}{0.79\ g/mL}\\\\V=10.12\ mL[/tex]

So, the volume of the object is 10.12 mL.

Answer:

BeO will have the greatest mass composition of oxygen

Explanation:

To solve this problem, we would find the mass composition of oxygen in each of the given sample.

To find this mass composition, let us derive the molecular mass of the given species;

  K₂O₂ = 2(39) + 2(16) = 110g/mol

  Na₂O = 2(23) + 16 = 62g/mol

   BeO = 9 + 16  = 25g/mol

Now; we know that mass of each sample is 1g;

mass composition of O in K₂O₂ = [tex]\frac{32}{110}[/tex] x  1= 0.29g

mass composition of O in Na₂O = [tex]\frac{16}{62}[/tex] x 1 = 0.26g

mass composition of O in BeO = [tex]\frac{16}{25}[/tex] x 1 = 0.64g

We can see that BeO will have the greatest mass composition of oxygen.

The mass composition of oxygen has been highest in BeO. Thus, option 3 is correct.

The molecular mass has been the mass of each element that has been present in the compound. The molecular mass of given compounds have been:

= 2 (39) + 2 (16)

= 110 g/mol

= 2 (23) + 16

= 62 g/mol

= 9 + 16

= 23 g/mol

The mass composition of oxygen in 1 gram of the following compounds have been:

Mass composition = [tex]\rm \dfrac{Mass\;of\;Oxygen}{Molecular\;mass\;of\;compound}\;\times\;weight\;of\;sample[/tex]

[tex]\rm K_2O_2[/tex] = 0.29 grams

[tex]\rm Na_2O[/tex] = 0.26 grams

BeO = 0.64 grams.

The mass composition of oxygen has been highest in BeO. Thus, option 3 is correct.

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Answer:

Calculate the mass of BR -79? Bromine has 2 naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu

Explanation:

if i get this wrong srry

okay so the  Answer is c