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3 years ago

CAN SOMEONE PLEASE HELP ME ASAP PLEASEE ANYBODY LITERALLY ANYONE OUT THERE PLEASE

Chemistry

1 answer:

hjlf3 years ago

6 0

The atomic number? If you mean in an atom, then the number of protons is the atomic number or proton number of an atom

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satellites orbiting earth use solar cells as their source of electrical energy. why are solar cells ideal energy sources foe sat

Yanka [14]

Solar cells are an ideal energy sources for satellites because they are always in contact of the sun's rays.

5 0

4 years ago

Why are the levels at the top smaller and the ones on the bottom larger in the energy pyramid? HELP ASAP

nalin [4]

Because as each organism goes up, there's less energy being given. Here's an example.

Take a plant, it has 100% of its energy. Then it's eaten by a deer, which could be the Primary Consumer. The deer has 10% of the beginning energy. Then, the deer is eaten by a wolf, a Secondary Consumer, which then has 1% of the energy.

3 0

3 years ago

The heat of combustion of propane, C3H8 (g) is -2057 kJ/mol. What would be the enthalpy change if enough propane was burned to g

Digiron [165]

Considering the reaction stoichiometry, the enthalpy change if enough propane was burned to give off 12 moles of carbon dioxide gas is 8228 kJ.

The balanced reaction is:

C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(l)

The heat of combustion of propane, C₃H₈, is -2057 kJ/mol. This is, 2057 kJ is released for every 1 mol C₃H₈.

So to determine the enthalpy change if enough propane was burned to emit 12 moles of carbon dioxide, you must take into account the stoichiometry of the reaction.

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

C₃H₈: 1 mole
O₂: 5 moles
CO₂: 3 moles
H₂O: 4 moles

Then you can apply the following rule of three: if by stoichiometry 3 moles of CO₂ are produced by 1 mole of C₃H₈, 12 moles of CO₂ are produced by how many moles of C₃H₈?

$amount of moles of C_{3} H_{8} =\frac{12 moles of CO_{2}x1 mole of C_{3} H_{8} }{3 moles of CO_{2}}$

amount of moles of C₃H₈= 4 moles

So to determine the enthalpy change, you can apply the following rule of three: If for each mole of C₃H₈ 2057 kJ are released, for 4 moles of C₃H₈ how much heat is released?

$Heat released=\frac{4 molesx2057 kJ}{1 mole}$

Heat released= 8228 kJ

The enthalpy change if enough propane was burned to give off 12 moles of carbon dioxide gas is 8228 kJ.

Learn more:

5 0

3 years ago

1. Determine the final volume of a 1.5 M HCl solution prepared from 20.0 mL

nadezda [96]

Explanation:

Because molarity is classified as moles of solute per liter of water, dilution of the water may result in a reduction of its concentration.

Therefore, because the amount of moles of solute has to be constant for dilution, you will use the molarity and volume of that same target solution to calculate how many moles of solute will be present in the sample of the stock solution that you dilute.

c = $\frac{n}{v}$

⇒ n = c ⋅ V

$n_{HCL}$ = 0.250 M ⋅ 6.00 L = 1.5 moles HCl

Now all you have to do is figure out what volume of 6.0 M stock solution will contain 1.5 moles of hydrochloric acid

c = $\frac{n}{v}$

V = $\frac{n}{c}$

$V_{Stock}$ = $\frac{1.5 moles}{6.0 \frac{moles}{L} }$ = 0.25 L

Expressed in milliliters, the answer will be

$V_{Stock} = 250ML$ → rounded to two sig figs

7 0

3 years ago

Aluminium oxide has a very high melting point (2072 degrees C) while carbon dioxide has a very low boiling point (-57 degrees C)

____ [38]

Answer:

Well, Aluminum Oxide has a very high melting point. Carbon dioxide has a very low boiling point.

Explanation:

They are both talking about different things, melting and boiling. Aluminum Oxide's melting point is much higher then carbon dioxide's melting point. Hope this help, and good luck on your assignment (if one)

5 0

4 years ago