Sea floor spreading occurs at a mid-ocean ridge true or false

Explanation:

number of moles=mass/molecular mass

molecular mass of calcium hydroxide=74

n=m/mr

=48.6/74

=0.65g/mol

I hope it helps

The number of moles of calcium hydroxide in a 48.6 g is 0.65 mol

The mole, symbol mol, is the SI base unit of amount of substance.

The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample.

Formula used :

Number of moles = mass / molecular mass

Molecular mass of calcium hydroxide = 74

n = m / mm

= 48.6 / 74

= 0.65 mol

Therefore, The number of moles of calcium hydroxide in a 48.6 g is 0.65 mol

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Answer:

The wavelength of the incoming photon is 172.8 nm

Explanation:

The wavelength of the incoming photon can be calculated with the photoelectric equation:

[tex] KE = h\frac{c}{\lambda_{p}} - \phi [/tex]   (1)

Where:

KE: is the kinetic energy of the electron

h: is Planck's constant = 6.62x10⁻³⁴ J.s  

c: is the speed of light = 3.00x10⁸ m/s

[tex]\lambda_{p}[/tex]: is the wavelength of the photon =?  

Φ: is the work function of the surface (Iron) = 4.5 eV        

The kinetic energy of the electron is given by:

[tex] KE = \frac{p^{2}}{2m} = \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} [/tex]  (2)

Where:  

p: is the linear momentum = h/λ

m: is the electron's mass = 9.1x10⁻³¹ kg

[tex]\lambda_{e}[/tex]: is the wavelength of the electron = 0.75 nm = 0.75x10⁻⁹ m

Hence, the wavelength of the photon is:

[tex] \frac{(\frac{h}{\lambda_{e}})^{2}}{2m} = h\frac{c}{\lambda_{p}} - \phi [/tex]

[tex]\lambda_{p} = \frac{hc}{\frac{h^{2}}{2m\lambda_{e}^{2}} + \phi} = \frac{6.62 \cdot 10^{-34} J.s*3.00\cdot 10^{8} m/s}{\frac{(6.62 \cdot 10^{-34} J.s)^{2}}{2*9.1 \cdot 10^{-31} kg*(0.75 \cdot 10^{-9} m)^{2}} + 4.5 eV*\frac{1.602 \cdot 10^{-19} J}{1 eV}} = 1.728 \cdot 10^{-7} m = 172.8 nm[/tex]      

Therefore, the wavelength of the incoming photon is 172.8 nm.

I hope it helps you!        

Respuesta:

4.26 M; 12.8 N

Explicación:

Primer paso: Calcular la concentración volumétrica (Cv)

Usaremos la siguiente expression.

Cv = Cg × ρ

Cv = 30 g%g × 1.39 g/mL = 41.7 g%mL

Segundo paso: Calcular la molaridad

La concentración volumetrica es 41.7 g%mL, es decir, hay 41.7 gramos de soluto cada 100 mL de solución. Usaremos la siguiente fórmula para molaridad.

M = masa de soluto / masa molar de soluto × litros de solución

M = 41.7 g / 97.99 g/mol × 0.1 L = 4.26 M

Tercer paso: Calcular la normalidad

Usaremos la siguiente fórmula.

N = M × Z

donde Z para un ácido es igual al número de protones.

N = M × Z

N = 4.26 mol/L × 3 eq/mol = 12.8 N

Answer:

Option C. 11

Explanation:

We'll begin by calculating the concentration of the hydroxide ion [OH¯] in the solution. This can be obtained as follow:

In solution, KOH will dissociate as follow:

KOH (aq) <=> K⁺(aq) + OH¯(aq)

From the balanced equation above,

1 mole of KOH reacted to produce 1 mole of OH¯.

Therefore, 1×10¯³ M KOH will also react to produce 1×10¯³ M OH¯.

Thus, the concentration of hydroxide ion [OH¯] in the solution is 1×10¯³ M

Next, we shall determine the pOH of the solution. This can be obtained as follow:

Concentration of hydroxide ion [OH¯] = 1×10¯³ M

pOH =?

pOH = –Log [OH¯]

pOH = –Log 1×10¯³

pOH = 3

Finally, we shall determine the pH of the solution. This can be obtained as follow:

pOH = 3

pH =?

pH + pOH = 14

pH + 3 = 14

Collect like terms

pH = 14 – 3

pH = 11

Answer:

hope this helps.answer is in the picture

Answer: A catalyst is a substance that speeds up the rate of a chemical reaction without being used up and remains chemically unchanged itself .

Explanation: For a reaction to take place the particles must collide with enough energy for bonds to break and reaction to occur .

BUT when a catalyst is present the reactants are able to react in a way that requires less energy ,leading to more successful collision so the reaction speeds up without the chemical composition of the catalyst being affected

NOTE: the catalyst must be chosen to suit the particular reaction

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Answer:

a. H2O: dihydrogen monoxide

b. PCl5: Phosphorus pentachloride

c. SiF4: Silicon tetrafluoride

d. N20: dinitrogen oxide

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:

0.68°C and 0°C.

Explanation:

The average freezing point of sucrose is 0.68°C whereas the average freezing point is 0°C. Both at these temperatures, turn from liquid into solid state. This point is also called transition point because at this point transition of state occurs of both compounds. When the temperature increases, this solid state is again turn into liquid form so temperature is responsible for this change of states of sucrose and water.

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:

0.32 liters/mole cm.

Explanation:

According to Beer Lambert's law;

A= εcl

ε = molar absorptivity

c= concentration

l= path length

A= 4.17*10^4 × 7.68*10^-6 × 1

A= 0.32 liters/mole cm.

Answer:

C6H12

Explanation:

Step 1: Find the molar mass of carbon dioxide and water

MH2O = 2(1.008) + 16.00 = 1.802x10^1 g/mol

MCO2 = 12.01 + 2(16.00) = 4.401x10^1 g/mol

Step 2: Calculate the moles of the products

nH2O = 108g / 1.802x10^1 g/mol = 5.99 or about 6

nCO2 = 264g/ 4.401x10^1 g/mol = 5.99 or about 6

Step 3: Enter moles of carbon dioxide and water into the balanced equation

CxH2x + O2 = 6CO2 + 6H2O

Step 4: Balance

We see how there is six carbon dioxide on the right side which means there are six carbons in the equation.

This means x is equal to 6 in our equation.

If you plug the information into the equation you get:

C6H12 + O2 = 6 CO2 + 6 H2O

Now all that's left is to balance the oxygens

We see how there is 18 oxygens on the right side of the equation which means there must be 18 on the left side.

Because we have oxygen gas we divide 18 by 2 which means there are 9 O2's on the left side

Therefore, the balanced equation is C6H12 + 9O2 = 6 CO2 + 6 H2O

Answer:

Phase C - Liquid State

Phase E - Gaseous State

Explanation:

Usually, in phases of water, we have the following;

When temperature is less than zero, it is said to be in its solid phase as ice.

When temperature is between 0 to 100, we can say it is in the liquid phase as water.

When temperature is above 100°C, It is said to be in the gaseous phase as vapour.

From the diagram;

Phase C is the only liquid state because it falls between temperature of 0°C and 100°

Also, only phase E is in the gaseous phase because the temperature is above 100°C.

Answer:

d. The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral.

Explanation:

According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electrons pairs surrounding the valence shell of the central atom in the molecule.

In CH3Cl, the central atom is carbon. Carbon has four regions of electron density surrounding it and no lone pairs. Lone pairs cause molecules to deviate from the expected geometry.

Since CH3Cl has no lone pairs on the carbon central atom, both the molecular and electron pair geometries are tetrahedral.

In CH₃Cl, the electron-pair geometry is trigonal-planar, and the molecular geometry is bent. Therefore, option C is correct.

According to VSEPR (Valence Shell Electron Pair Repulsion) theory, the electron pairs around the central atom in CH₃Cl will arrange themselves to minimize repulsion, resulting in a specific geometry.

In CH₃Cl, the central atom is carbon (C), and it is surrounded by three hydrogen atoms (H) and one chlorine atom (Cl).

The electron-pair geometry is determined by the arrangement of these electron pairs.

Molecular geometry considers only the atoms around the central atom, not the lone pairs.

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Answer: i Choose the sun

because it has mass

Explanation: matter is anything that has mass and occupies space / Volume

and the sun has mass though it is not a solid one, and is made up of matter

HOPE THIS HELPSS!!!!

Answer:

I think it is C

Explanation:

Hope this helps!! :)

If I'm wrong, then greatest apologies

Answer:

I don't know yr language

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

nobody can say it is uncertain but in my opinion it will grow quickly in the next 10 years

The ionization constant of an acid is denoted by the symbol Kₐ. The smaller the value of Kₐ for an acid, the weaker will be the acid. Thus the correct option is D.

The acid dissociation constant denotes the measure of the extent to which an acid dissociates in the solution. The strength of an acid is represented by the value Kₐ. The less an acid dissociates, smaller will be the value of Kₐ, the stronger the acid, higher will be the value of Kₐ.

The dissociation of HNO₂ is given as:

HNO₂ (aq) ⇄ H⁺ (aq) + NO₂⁻ (aq)

The dissociation constant of HNO₂ is given as:

Kₐ = [H⁺][NO₂⁻] / HNO₂

The value of Kₐ is constant at a particular temperature. We can use this fact to find out the pH of a weak acid at a particular temperature.

Thus the correct option is D.

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Answer:

C

Explanation:

∂S represents change in entropy.

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:

net ionic equation

[tex]\boxed{ SO_4{}^{2-} {}_{(aq.)} + Ba^{2+} {}_{(aq.)} \rightarrow BaSO_4 {}_{(s)}} [/tex]

Explanation:

Given the amount of fluorine is ---- 1.25 mol.

What is the mass of given fluorine in grams?

Since

[tex]Number of moles =\frac{given mass of the substance}{its molecular mass}[/tex]

To get the mass of the substance in grams, multiply the given number of moles with the molecular mass of the substance.

Hence, among the given options, the correct answer is the last option that is

Multiply the atomic mass of fluorine by 1.25.

Answer:

Multiply the atomic mass of fluorine by 1.25.

Explanation:

i got it right on the exam!! :)

Answer:

the reaction between vinegar and baking soda, the reactants are vinegar (acetic acid) and baking soda (sodium bicarbonate). The products are sodium acetate, water, and carbon dioxide gas.

Explanation:

P_H

and

li_n

hope it helps