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3 years ago

Which statements describe the principles of the big bang theory? Check all that apply.

2 answers:

8 0

The big bang theory explains how the universe began. According to it, the universe began as singularity (a very hot , small and dense superforce with no stars, atoms, or structures) and then about 13.7 billion years ago, the space expanded very quickly. This leads to formation of stars and galaxies which we know today. This expanding of universe is still happening and thus the temperature of universe is decreasing.

Therefore, the statements describing the bing bang theory are:

1) The universe is continuing to expand and

2)A massive explosion caused matter and energy to expand and form the universe.

amid [387]3 years ago

5 0

Answer:

The Universe is continuing to expand.

A Massive explosion caused matter and energy to be destroyed.

You might be interested in

Which can not be decomposed by a chemical change? 1) a compound 2) a heterogeneous mixture 3) a homogeneous mixture 4) an elemen

Mnenie [13.5K]

4.) an element cannot be decomposed by a chemical change, it is a pure substance and no other materials compose it.

3 0

3 years ago

In which orbital does an electron in a bromine atom experience the greatest effective nuclear charge?

asambeis [7]

First let us determine the electronic configuration of Bromine (Br). This is written as:

Br = [Ar] 3d10 4s2 4p5

Then we must recall that the greatest effective nuclear charge (also referred to as shielding) greatly increases as distance of the orbital to the nucleus also increases. So therefore the electron in the farthest shell will experience the greatest nuclear charge hence the answer is:

<span>4p orbital</span>

4 0

3 years ago

Read 2 more answers

While ethanol is produced naturally by fermentation, e.g. in beer- and wine-making, industrially it is synthesized by reacting e

sp2606 [1]

The question is incomplete, here is the complete question:

While ethanol is produced naturally by fermentation, e.g. in beer- and wine-making, industrially it is synthesized by reacting ethylene with water vapor at elevated temperatures.

A chemical engineer studying this reaction fills a 1.5 L flask at 12°C with 1.8 atm of ethylene gas and 4.7 atm of water vapor. When the mixture has come to equilibrium she determines that it contains 1.16 atm of ethylene gas and 4.06 atm of water vapor.

The engineer then adds another 1.2 atm of ethylene, and allows the mixture to come to equilibrium again. Calculate the pressure of ethanol after equilibrium is reached the second time. Round your answer to 2 significant digits.

<u>Answer:</u> The partial pressure of ethanol after equilibrium is reached the second time is 1.0 atm

<u>Explanation:</u>

We are given:

Initial partial pressure of ethylene gas = 1.8 atm

Initial partial pressure of water vapor = 4.7 atm

Equilibrium partial pressure of ethylene gas = 1.16 atm

Equilibrium partial pressure of water vapor = 4.06 atm

The chemical equation for the reaction of ethylene gas and water vapor follows:

$CH_2CH_2(g)+H_2O(g)\rightleftharpoons CH_3CH_2OH(g)$

<u>Initial:</u> 1.8 4.7

<u>At eqllm:</u> 1.8-x 4.7-x

Evaluating the value of 'x'

$\Rightarrow (1.8-x)=1.16\\\\x=0.64$

The expression of $K_p$ for above equation follows:

$K_p=\frac{p_{CH_3CH_2OH}}{p_{CH_2CH_2}\times p_{H_2O}}$

$p_{CH_2CH_2}=1.16atm\\p_{H_2O}=4.06atm\\p_{CH_3CH_2OH}=0.64atm$

Putting values in above expression, we get:

$K_p=\frac{0.64}{1.16\times 4.06}\\\\K_p=0.136$

When more ethylene is added, the equilibrium gets re-established.

Partial pressure of ethylene added = 1.2 atm

$CH_2CH_2(g)+H_2O(g)\rightleftharpoons CH_3CH_2OH(g)$

<u>Initial:</u> 2.36 4.06 0.64

<u>At eqllm:</u> 2.36-x 4.06-x 0.64+x

Putting value in the equilibrium constant expression, we get:

$0.136=\frac{(0.64+x)}{(2.36-x)\times (4.06-x)}\\\\x=0.363,13.41$

Neglecting the value of x = 13.41 because equilibrium partial pressure of ethylene and water vapor will become negative, which is not possible.

So, equilibrium partial pressure of ethanol = (0.64 + x) = (0.64 + 0.363) = 1.003 atm

Hence, the partial pressure of ethanol after equilibrium is reached the second time is 1.0 atm

3 0

3 years ago

Which reaction has the highest atom economy for the production of C02?

In-s [12.5K]

The highest atom economy

2CO + O₂ ⇒ 2CO₂

<h3>Further explanation</h3>

Given

The reaction for the production of CO₂

Required

The highest atom economy

Solution

In reactions, there are sometimes unwanted products that can be said to be a by-product or a waste product. Meanwhile, the desired product can be said to be a useful product, which can be shown as the atom economy

of the reaction

the higher the atomic economy value of a reaction, the smaller the waste/ byproducts produced, so that less energy is wasted

The general formula:

Atom economy = (mass of useful product : mass of all reactants/products) x 100

Atom economy = (total formula masses of useful product : total formula masses of all reactants/products) x 100

So a reaction that only produces one product will have the highest atomic value, namely the reaction in option C

4 0

2 years ago

How do I calculate the molecular weight of Mg(OH)2?

vodomira [7]

The molecular weight of Mg(OH)2 : 58 g/mol

<h3>Further explanation</h3>

Given

Mg(OH)2 compound

Required

The molecular weight

Solution

Relative atomic mass (Ar) of element : the average atomic mass of its isotopes

Relative molecular weight (M) : The sum of the relative atomic mass of Ar

M AxBy = (x.Ar A + y. Ar B)

So for Mg(OH)2 :

= Ar Mg + 2 x Ar O + 2 x Ar H

= 24 g/mol + 2 x 16 g/mol + 2 x 1 g/mol

= 24 + 32 + 2

= 58 g/mol

5 0

2 years ago