Explain why a solar eclipse occurs only during a new Moon

How much work (in JJ) is required to expand the volume of a pump from 0.0 LL to 2.5 LL against an external pressure of 1.1 atmat

stira [4]

Answer:

- 278.85 J

Explanation:

Given that:

Pressure = 1.1 atm

The initial volume V₁ = 0.0 L

The final volume V₂ = 2.5 L

The work that takes place in a reaction at constant pressure can be expressed by using the equation:

W = P(V₂ - V₁ )

Since the volume of the gas is expanded from 0 to 2.5 L when 1.1 atm pressure is applied. Then, the work can be given by the expression:

W = - P(V₂ - V₁ )

W = -1.1 atm ( 2.5 - 0.0) L

W = -1.1 atm (2.5 L)

W = -2.75 atm L

Recall that:

1 atm L = 101.4 J

Therefore;

-2.75 atm L = ( -2.75 × 101.4 )J

= -278.85 J

Thus, the work required at the chemical reaction when the pressure applied is 1.1 atm = - 278.85 J

8 0

3 years ago

HELPPP What method should you use to separate this sample of mixture?

kozerog [31]

Answer:

The answer to your question is: D. Fractional distillation

Explanation:

A. Column chromatography this method is use to separate mixtures base in its capacity to be absorbed.

B. Fractional crystallization this method use the solubility of solutes in a solvent.

C. Simple distillation is a method to separate 2 liquids based on the difference in their boiling points.

D. Fractional distillation is a method used to separate a mixture of liquids which have their boiling points very close.

E. Paper chromatography is a method to separate a mixture based on their different rate of migration on a paper.

8 0

3 years ago

Consider the following reaction: 2CH3OH(g)  2CH4(g) + O2(g) ΔH = +252.8 kJ a) Calculate the amount of heat transferred when 24.

denpristay [2]

Answer:

For a: The amount of heat transferred for the given amount of methanol is 94.6736 kJ.

For b: The mass of methane gas produced will be 10.384 g.

Explanation:

For the given chemical reaction:

$2CH_3OH(g)\rightarrow 2CH_4(g)+O_2(g);\Delta H=+252.8kJ$

For a:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

Given mass of methanol = 24.0 g

Molar mass of methanol = 32.04 g/mol

Putting values in above equation, we get:

$\text{Moles of methanol}=\frac{24.0g}{32.04g/mol}=0.749mol$

By Stoichiometry of the reaction:

For every 2 moles of methanol, the amount of heat transferred is +252.8 kJ.

So, for every 0.749 moles of methanol, the amount of heat transferred will be = $\frac{252.8}{2}\times 0.749=94.6736kJ$

Hence, the amount of heat transferred for the given amount of methanol is 94.6736 kJ.

For b:

By Stoichiometry of the reaction:

252.8 kJ of energy is absorbed when 2 moles of methane gas is produced.

So, 82.1 kJ of energy will be absorbed when = $\frac{2}{252.8}\times 82.1=0.649mol$ of methane gas is produced.

Now, calculating the mass of methane gas from equation 1, we get:

Molar mass of methane gas = 16 g/mol

Moles of methane gas = 0.649 moles

Putting values in equation 1, we get:

$0.649mol=\frac{\text{Mass of methane gas}}{16g/mol}\\\\\text{Mass of methane}=10.384g$

Hence, the mass of methane gas produced will be 10.384 g.

7 0

4 years ago

Round off 0.0008769 to three significant digits.

garik1379 [7]

8.769 x 10^-4
it will be your answer

6 0

3 years ago

Predict the products of each of the following reactions and then balance the chemical equations.

Nookie1986 [14]

Answer: The chemical equations are given below.

Explanation:

For a: Fe is heated in an atmosphere of steam.

The chemical equation follows:

$3Fe(s)+4H_2O(g)\rightarrow Fe_3O_4(s)+4H_2(g)$

By Stoichiometry of the reaction:

3 moles of iron reacts with 4 moles of steam to produce 1 mole of iron (II,III) oxide and 4 moles of hydrogen.

For b: NaOH is added to a solution of $Fe(NO_3)_3$

The chemical equation follows:

$Fe(NO_3)_3+3NaOH\rightarrow Fe(OH)_2+3NaNO_3$

By Stoichiometry of the reaction:

1 mole of iron nitrate reacts with 3 moles of sodium hydroxide to produce 1 mole of iron hydroxide and 3 moles of sodium nitrate.

For c: $FeSO_4$ is added to an acidic solution of $KMnO_4$

The chemical equation follows:

$10FeSO_4+2KMnO_4+8H_2SO_4\rightarrow 5Fe_2(SO_4)_3+K_2SO_4+2MnO_4+8H_2O$

By Stoichiometry of the reaction:

10 moles of iron(II) sulfate reacts with 2 moles of potassium permangante and 8 moles of sulfuric acid to produce 5 moles of iron(III) sulfate, 1 mole of potassium sulfate, 2 moles of manganese oxide and 8 moles of water.

For d: Fe is added to a dilute solution of $H_2SO_4$

The chemical equation follows:

$Fe+H_2SO_4\rightarrow FeSO_4+H_2$

By Stoichiometry of the reaction:

1 mole of iron reacts with 1 mole of sulfuric acid to produce 1 mole of iron sulfate and 1 mole of hydrogen gas.

For e: A solution of $Fe(NO_3)_2$ and $HNO_3$ is allowed to stand in air.

The chemical equation follows:

$3Fe(NO_3)_2+4HNO_3\rightarrow 3Fe(NO_3)_3+NO+H_2O$

By Stoichiometry of the reaction:

3 moles of iron(II) nitrate reacts with 4 moles of nitric acid to produce 3 moles of iron(III) nitrate, 1 mole of nitric oxide and 1 mole of water.

For f: $FeCO_3$ is added to a solution of $HClO_4$

The chemical equation follows:

$FeCO_3+2HClO_4\rightarrow Fe(ClO_4)_2+CO_2+H_2O$

By Stoichiometry of the reaction:

1 mole of iron(II) carbonate reacts with 2 moles of perchloric acid to produce 1 moles of iron(II) perchlorate, 1 mole of carbon dioxide and 1 mole of water.

For g: Fe is heated in air

The chemical equation follows:

$2Fe+O_2\rightarrow 2FeO$

By Stoichiometry of the reaction:

2 moles of iron reacts with 1 mole of oxygen gas to produce 2 moles of iron(II) oxide.

Hence, the chemical equations are given above.

7 0

3 years ago