someone help please this is due today!!?

Answer:

See explanation

Explanation:

The percentage by mass of oxygen is defined as;

Mass of oxygen/ molar mass of the compound * 100/1

The average percentage by mass of oxygen = 38.933 + 38.940 + 38.871 + 38.892 + 38.900/5

The average percentage by mass of oxygen = 38.907

Percentage Error  = (|accepted value – experimental value| \ accepted value) x 100%

Percentage Error  = 39.13 - 38.907 / 39.13 * 100

Percentage Error  = 0.57%

Answer:

0.389 M

Explanation:

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

Mass of CuCl₂ = 78.5 g

Volume of solution = 1.50 L

Molarity of CuCl₂ =?

Next, we shall determine number of mole in 78.5 g of CuCl₂. This can be obtained as follow:

Molar mass of CuCl₂ = 63.5 + (35.5×2)

= 63.5 + 71

= 134.5 g/mol

Mass of CuCl₂ = 78.5 g

Number of mole of CuCl₂ =?

Mole = mass / Molar mass

Number of mole of CuCl₂ = 78.5 / 134.5

Number of mole of CuCl₂ = 0.584 mole

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

Number of mole of CuCl₂ = 0.584 mole

Volume of solution = 1.50 L

Molarity of CuCl₂ =?

Molarity = mole / Volume

Molarity of CuCl₂ = 0.584 / 1.50

Molarity of CuCl₂ = 0.389 M

The molarity of a solution that contains 78.5 g of copper(II) chloride in 1.50 L of solution is 0.389M.

The molarity of a solution can be calculated

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

Next, we shall determine number of moles in 78.5g of CuCl₂. This can be obtained as follow:

Molar mass of CuCl₂ = 63.5 + (35.5×2)

= 63.5 + 71

= 134.5 g/mol

Mass of CuCl₂ = 78.5g

Number of mole of CuCl₂ = 78.5 / 134.5

Number of mole of CuCl₂ = 0.584 moles

The determine the molarity of the solution. This can be obtained as follow:

Molarity = mole / Volume

Molarity of CuCl₂ = 0.584 / 1.50

Molarity of CuCl₂ = 0.389M

Therefore, molarity of a solution that contains 78.5 g of copper(II) chloride in 1.50 L of solution is 0.389M.

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Answer:

im absoulutely positive it is C

A higher density water will be obtained in lower temperature water.

Density is the fluid property that describes the amount of solutes that dissolves in a given volume of the fluid.

Density of a fluid is calculated by taking the ratio of mass to volume of the fluid.

[tex]\rho = \frac{m}{v}[/tex]

When the temperature of the water is low, more mass of the water is obtained while a high temperature evaporates the liquid.

Thus, a higher density water will be obtained in lower temperature water.

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Brenda argument is supported.

Here moss and lichens are still there after the flood which will recolonize the colony once there.

Primary succession is ecological succession that begins in essentially lifeless areas, such as regions in which there is no soil or where the soil is incapable of sustaining life.

It is a type of ecological succession in which plants and animals recolonize a habitat after a major disturbance such as a devastating flood, wildfire, landslide, lava flow, flood or human activity.

To know more about ecological succession here

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#SPJ2

Answer:

The total change in enthalpy for the reaction is - 81533.6 J/mol

Explanation:

Given the data in the question;

Reaction;

HCl + NaOH → NaCl + H₂O

Where initial temperature is 21.2 °C and final temperature is 28.0 °C. Ccal is 1234.28 J

Moles of NaOH  = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol

Moles of HCl = 50.mL × 1.00 M = 50.0 mmol = 0.0500 mol

so, 0.0500 moles of H₂O produced

Volume of solution = 50.mL  +  50.mL  = 100.0 mL

Mass of solution m = volume × density = 100.0mL × 1.0 g/mL = 100 g

now ,

Heat energy of Solution q= (mass × specific heat capacity × temp Δ) + Cal

we know that; The specific heat of water(H₂O) is 4.18 J/g°C.

so we substitute

q_soln = (100g × 4.18 × ( 28.0 °C - 21.2 °C) ) + 1234.28

q_soln = 2842.4 + 1234.28

q_soln = 4076.68 J

Enthalpy change for the neutralization is ΔH[tex]_{neutralization}[/tex]

ΔH[tex]_{neutralization}[/tex] = -q_soln / mole of water produced

so we substitute

ΔH[tex]_{neutralization}[/tex] = -( 4076.68 J ) / 0.0500 mol  

ΔH[tex]_{neutralization}[/tex] = - 81533.6 J/mol

Therefore, the total change in enthalpy for the reaction is - 81533.6 J/mol

Answer:

The answer is (a)

.

.

......................................................................

Answer:

pump that is the answer hope its right

Answer:

96.09 g/mol

Explanation:

Answer: the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

Explanation:

Given the data in the question;

I think the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has more charge that is +2 and -2 respectively when compared to Kcl which has +1 and -1 charge.so it will be more negative.

radius = r[tex]_{ca+2}[/tex] + r[tex]_{s-2}[/tex] = 100 + 184 = 284 pm = 2.84 × 10⁻¹⁰ m

we know that; k = 2.31 × 10⁻²⁸ J

q1 = 2  ( charge on Ca⁺² )

q2 = -2( charge on S⁻²)

so

Ep = k × q1q2/r

so we substitute

Ep = 2.31 × 10⁻²⁸ × (+2×-2) / 2.84 × 10⁻¹⁰

Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰

Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰

Ep = -3.26 × 10⁻¹⁸ J

Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

Based on the data provided, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J

The electrostatic potential energy is the work done in moving the charge from infinity to that point against the electric field.

The electrostatic potential energy between any two charges q1, q2 separated by distance r is derived from Coulomb’s law and mathematically given as:

where

From the data provided:

ionic radii of Ca2+ r1 = 100 pm

ionic radii of S2– = 184 pm.

Chargeon Ca2+ = +2

Charge on S2_ = -2

From the data above, it most likely that the value of electrostatic potential energy of calcium sulfide CaS formed will be less(more negative) than KCl because the Ca2+ and S2- ions has a greater charge of +2 and -2 respectively compared to Kcl which has +1 and -1 charge.

Calculating the electrostatic potential energy, Ep:

radius = r1 + r2 = 100 + 184 = 284 pm

r = 2.84 × 10⁻¹⁰ m

k = 2.31 × 10⁻²⁸ J

q1 = 2  ( charge on Ca⁺² )

q2 = -2( charge on S⁻²)

Then:

Ep = k × q1q2/r

Substituting the values above in the equation:

Ep = 2.31 × 10⁻²⁸ × (+2 ×-2) / 2.84 × 10⁻¹⁰

Ep = (2.31 × 10⁻²⁸ × -4) / 2.84 × 10⁻¹⁰

Ep = -9.24 × 10⁻²⁸ / 2.84 × 10⁻¹⁰

Ep = -3.26 × 10⁻¹⁸ J

Therefore, the electrostatic potential energy is -3.26 × 10⁻¹⁸ J.

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Answer:0

.63

Explanation:

Answer:

mole ratio, which is equivalent to a 1;1 mole ratio, to a gram ratio. This means that when the reaction consumes 84.03 g of carbon monoxide, it should theoretically produce 132.03 g of carbon dioxide. Use this gram ratio to calculate the theoretical yield for your reaction.

Explanation:

Answer:

the enantiomeric excess of the mixture is 40%

Explanation:

The computation of the enantiomeric excess of the mixture is shown below:

As we know that

[tex]= |\frac{R - S}{R + S} |\times 100\\\\= |\frac{70 - 30}{70 + 30}| \times 100\\\\= 40\%[/tex]

Hence, the enantiomeric excess of the mixture is 40%

Explanation:

i believe this is right. my bad if its not

Answer:

true

Explanation:

it is because hormone determines various factors

Answer:

particles

atoms

broken

isotope

conductors

electricity

element

combined

Answer:

Hello your question is poorly written hence i will give you a more general answer

answer :  The reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,

Explanation:

Natural Precipitation occurs when condensed atmospheric water vapor falls due to the gravitational pull exerted on it by the clouds. precipitation can be in various forms like ; rain , ice pellets and snow . e.t.c

Hence the reason why it is desirable to use an excess of barium ion in the precipitation is to form the compound needed,

Also in order to form the precipitation, we will also add excess of barium ion which will help form the required precipitate and also  filter out the mass of Sulphate.

Answer:

1. H2 + Cl2 => 2HCl

2. Na2S + 2HCl => 2NaCl + H2S

3. 6HCl + 2Al => 2AlCl3 + 3H2

4. C3H8 + 5O2 => 3CO2 + 4H2O

5. C6H12O6 + 6O2 => 6CO2 + 6H2O

6. 4C12H23O11 + 49O2 => 48CO2 + 46H2O

7. 4NH3 + 7O2 => 4NO2 + 6H2O

8. 2Mg + 02 => 2MgO

hope it helps

Answer:It is the ground state of NA

Answer:

the answer to this question is A H202

Answer:

11.7

Explanation:

The pH is the negative logarithm of the concentration of H+ ions. If the concentration is 2×10-¹² the the pH will be -log(2×10-¹²) which is 11.698 which can be round up to 11.7.

In the first box, you should draw a chicken. In the second box, you should draw a cow or a horse.

I hope it helps you!!!! :D

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Answer:

true

Explanation:

Prophase is the first stage in mitosis, occurring after the conclusion of the G2 portion of interphase. During prophase, the parent cell chromosomes which were duplicated during S phase condense and become thousands of times more compact than they were during interphase.

Answer:

0.263 mol

Explanation:

K2SO4 - potassium sulfate

Molar mass (K2SO4) = 2*39.0983 + 32.065 + 4*15.9994 =

= 174.2592≈174.26 g/mol

45.8 g * 1 mol/174.26 g = 0.263 mol