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2 years ago

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I GIVE BRAINLY Which statement best defines visible light? (1 point) O a type of atom found in energy O a form of energy that al

lows people to see O a distance between one part of a wave and another O a change in direction of light when it strikes an object

1 answer:

jekas [21]2 years ago

8 0

Answer: A form of energy that allows people to see

Explanation:

Nicki Minaj

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Al2(SO4)3(s) + H2O(l) ---- Al2O3(s) + H2SO4 (aq) calculate enthalpy formation for this reaction. Balance the reaction. Calculate

katen-ka-za [31]

The given chemical equation is:

$Al_{2}(SO_{4})_{3}(aq)+H_{2}O(l)-->Al_{2}O_{3}(aq)+H_{2}SO_{4}(aq)$

On balancing the equation we get,

$Al_{2}(SO_{4})_{3}(aq)+3H_{2}O(l)-->Al_{2}O_{3}(aq)+3H_{2}SO_{4}(aq)$

Calculating enthalpy of formation of this reaction from the standard heats of formation of the products and reactants:

Δ $H_{reaction}^{0}=[H_{f}^{0}(Al_{2}O_{3}(s)) + (3*H_{f}^{0}(H_{2}SO_{4}(aq))] - [H_{f}^{0}(Al_{2}SO_{4}(aq)) + (3*H_{f}^{0}(H_{2}O(l))]$

=[(-1669.8kJ/mol)+ {3* (-909.27 kJ/mol)}]-[(-3442kJ/mol)+{3*(-285.8 kJ/mol)}]

=[(-4397.61kJ/mol)]-[(-4299.4kJ/mol)]

=-98.21kJ/mol

Total enthalpy change when 15 mol of $Al_{2}(SO_{4})_{3}$ reacts will be=

$15 mol Al_{2}(SO_{4})_{3}*\frac{-98.21kJ}{1 molAl_{2}(SO_{4})_{3}} =-1473.15kJ/mol$

4 0

4 years ago

Which of the following would be the most likely adaptation of a whale population to tolerate a rise in ocean temperatures?

GREYUIT [131]

It is better for the whales to go where the whales have the ability to dive longer and deeper to find cooler water.

5 0

3 years ago

Sea water, a solution composed of a variety of salts dissolved in water. The salt is the . Soda water, a solution composed of ca

VladimirAG [237]

Answer:

In sea water;

The salt is the solute while the water is the solvent

In soda water;

The water is the solvent, the carbon dioxide is the solute

In air;

The nitrogen is the solvent while the oxygen and the other substances in small amounts are the solutes

Explanation:

A solution is a homogeneous mixture of two or more substances which includes a solvent and a solute. A solute in a solution is dissolved in the solvent of the solution.

Therefore, the solvent is the major part of a solution as it takes in the solvent to form the solution.

In sea water, a solution with a high concentration of salts

The salt is the solute while the water is the solvent

In soda water, which is a mixture of CO₂ in water,

Here we have in the soda solution, the water is the solvent while the carbon dioxide is the solute

The water is the solvent, the carbon dioxide is the solute

Air a solution made up by a mixture of Nitrogen 78%, oxygen 21%, and small amount of water carbon dioxide and argon

The nitrogen is the solvent while the oxygen and the other substances in small amounts are the solutes.

8 0

3 years ago

Which shell would be complete with 10 electrons?

nlexa [21]

Answer:

The answer to your question is letter d

Explanation:

If we remember there is a limit of electrons that can be place in a sublevel

Sublevel s only accept 2 electrons

Sublevel p only accept 6 electrons

Sublevel d only accept 10 electrons

Sublevel f only accept 14 electrons

This is in agreement wth the levels of energy, that only accept a determine number of electrons

Level Sublevel # of electrons

1 s 2

2 s and p 8 (2 + 6)

3 s, p and d 18 (2+6+10)

4 s, p, d, f 32 (2+6+10+14)

5 s, p, d,f 32 (2+6+10+14)

6 s, p, d 18 (2+6+10)

7 s, p 8 (2+6)

3 0

3 years ago

A piece of fossilized wood has a carbon-14 radioactivity that is 1/4 that of new wood. the half-life of carbon-14 is 5730 years.

Marizza181 [45]

Answer:

1.146 x 10⁴ year.

Explanation:

The decay of carbon-14 is a first order reaction.

The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.

The integration law of a first order reaction is:

<em>kt = ln [A₀]/[A]</em>

<em></em>

k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.

t is the time = ??? years.

[A₀] is the initial percentage of carbon-14 = 100.0 %.

[A] is the remaining percentage of carbon-14 = 1/4[A₀] = 25.0 %.

∵ kt = ln [Ao]/[A]

∴ (1.21 x 10⁻⁴ year⁻¹)(t) = ln (100.0%)/[25.0 %]

(1.21 x 10⁻⁴ year⁻¹)(t) = 1.386.

∴ <em>t </em>= 1.386/ (1.21 x 10⁻⁴ year⁻¹) = <em>1.146 x 10⁴ year.</em>

3 0

4 years ago