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3 years ago

Lunar Eclipse. Choose ALL that apply

Chemistry

2 answers:

antoniya [11.8K]3 years ago

6 0

Answer:

b and a i jus did it

Explanation: none

Ronch [10]3 years ago

5 0

Answer:

the answer to 1 is all the answers

the 2 one is Moon moves between the sun and Earth and The moon blocks out the light of the sun and casts a shadow onto the Earth

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Consider the reaction: 2HI(g) ⇄ H2(g) + I2(g). It is found that, when equilibrium is reached at a certain temperature, HI is 35.

Sliva [168]

Answer:

Kc = 0.075

Explanation:

The dissociation (α) is the initial quantity that ionized divided by the total dissolved. So, let's calling x the ionized quantity, and M the initial one:

α = x/M

x = M*α

x = 0.354M

For the stoichiometry of the reaction (2:1:1), the concentration of H₂ and I₂ must be half of the acid. So the equilibrium table must be:

2HI(g) ⇄ H₂(g) + I₂(g)

M 0 0 Initial

-0.354M +0.177M +0.177M Reacts

0.646M 0.177M 0.177M Equilibrium

The equilibrium constant Kc is the multiplication of the products' concentrations (elevated by their coefficients) divided by the multiplication of the reactants' concentrations (elevated by their coefficients):

$Kc = \frac{[H2]*[I2]}{[HI]^2}$

$Kc = \frac{0.177M*0.177M}{(0.646M)^2}$

$Kc = \frac{0.03133M^2}{0.41732M^2}$

Kc = 0.075

5 0

3 years ago

Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

Paha777 [63]

Answer:

There is 9671 Kj of heat released

Explanation:

Step 1: The balanced equation:

C18H36O2(s) + 26O2(g) --> 18CO2(g)+18H2O(g)

This means for 1 mole of C18H36O2 consumed there is 26 moles of O2 needed to produce 18 moles of CO2 and 18 moles of H2O.

Step 2: Calculate the heat of combustion

ΔH (combustion) = [18*(ΔHf of CO2) + 18*(ΔHf of H2O)] - [1*(ΔHf of C18H36O2) + 26*(ΔHf of O2)]

ΔH (combustion) = [18*(-394 kJ/mol) + 18*(-242 kJ/mol)] - [1*(-948 kJ/mol) + 26*(0 kJ/mol)]

ΔH (combustion) = [(-7092 kJ/mol) + (-4356 kJ/mol)] - (-948 kJ/mol)

= -10500 kJ/mol

ΔH (combustion) = heat released / number of moles of stearic acid

Step 3: Calculate moles of stearic acid

moles of stearic acid = mass / Molar mass of stearic acid

moles of stearic acid = 262g / 284.48 g/mole = 0.921 moles

Step 4: Calculate moles of oxygen

moles of O2 = 914.5 / 32g/mole

moles of O2 = 28.578125 moles

Stearic acid is the limiting reactant: it will completely react

There will react 26*0.921 mole = 23.946 mole of O2

This means there will remain 4.63 moles of O2

Step 5: Calculate heat released

q = (ΔH combustion) * (moles of stearic acid) = (-10500 kJ/mol) * (0.921 moles) = 9671 Kj

There is 9671 Kj of heat released

6 0

3 years ago

A metal sample has a mass of 64.2 g. What is the density of this metal?

brilliants [131]

density= mass/volume

we need the volume of the metal to find the density, in which case the answer would be 64.2/volume=density

8 0

3 years ago

Which methods will help you properly identify pH with indicator paper? Check all that apply. Set a piece of pH paper in front of

monitta

Set a piece of pH paper in front of each solution before testing to keep organized.

Use a transfer pipet to remove a few drops from the solution to drop onto the paper.

Wait a minute or so before reading color.

Is the correct answer...

4 0

3 years ago

Read 2 more answers

Write a balanced equation for rusting. (Assume rust becomes Fe+2)

Stells [14]

Answer:

4Fe + 3O2 + 6H2O → 4Fe(OH)3

Explanation:

The chemical formula for rust is Fe2O3 and is commonly known as ferric oxide or iron oxide. The final product is a series of chemical reactions simplified below as- The rusting of the iron formula is simply 4Fe + 3O2 + 6H2O → 4Fe(OH)3. The rusting process requires both the elements of oxygen and water.

8 0

3 years ago