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3 years ago

What is consciousness? ...

1 answer:

5 0

Consciousness is the status of being aware of your surroundings and are awake

We dream because our brain creates mental images. We even dream about things that are unwelcome in our dreams.

Certain Stuff is there to help you. Others are there to bring you down.

Yes there are other universes. There’s a whole endless walk out there other than this cruel world.

You might be interested in

Find the enthalpy of neutralization of HCl and NaOH. 137 cm3 of 2.6 mol dm-3 hydrochloric acid was neutralized by 137 cm3 of 2.6

liraira [26]

Answer : The correct option is, (D) 89.39 KJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.3562 mole of HCl neutralizes by 0.3562 mole of NaOH

Thus, the number of neutralized moles = 0.3562 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $137ml+137ml=274ml$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 274ml=274g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 274 g

$T_{final}$ = final temperature of water = 325.8 K

$T_{initial}$ = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

$q=274g\times 4.18J/g^oC\times (325.8-298)K$

$q=31839.896J=31.84KJ$

Thus, the heat released during the neutralization = -31.84 KJ

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -31.84 KJ

n = number of moles used in neutralization = 0.3562 mole

$\Delta H=\frac{-31.84KJ}{0.3562mole}=-89.39KJ/mole$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 89.39 KJ/mole

3 0

3 years ago

Photochemical smog is formed when primary pollutants interact with

ivolga24 [154]

Answer: Sunlight.

Explanation:

Photochemical smog is formed when primary pollutants such nitrogen oxides and volatile organic compound (VOC) react with sunlight, forming a brown haze above cities.

Photochemical smog can only occur during the day.

5 0

3 years ago

How is enthalpy related to the spontaneity of a reaction?

mina [271]

Answer:

Explanation:

Gibb's free energy change(∆G) and Standard electrode potential of electrochemical (Ecell) determine the spontaneity of a reaction.

when ∆G > 0, the reaction is not spontaneous

∆G < 0, the reaction is spontaneous

∆G = 0, the reaction is in equilibrium

when Ecell > 0, the redox reaction is spontaneous

Ecell < 0, the redox reaction is not spontaneous

Ecell = 0, the redox reaction is in equilibrium.

5 0

2 years ago

Stoichiometry<br> Please show how to get this I don't understand any part of it!!

tatiyna

Answer:

The following is a rather lengthy discussion on chemical stoichiometry, but it will lead you through the mole concept and its application to chemical reaction stoichiometry. The problems are different than the one posted, but if you can follow this, then you can work your problem of interest.

Explanation:

Stoichiometry is very easy to master if you understand the ‘mole concept’ and how it is used to define and describe chemical process mathematically. A ‘mole’ – in chemistry – is the mass of substance containing one Avogadro’s Number of particles. That is, N₀ = 6.023 x 10²³ particles / mole. When working with chemical reactions and equations data should be first converted to moles using the following conversions.

1 mole = 1 formula weight = 6.023 x 10²³ particles = 22.4 liters at STP(0⁰, 1atm).

In this problem you are given the equation 2Na + 2H₂O => 2NaOH + H₂. ‘Reading the equation’ there are 2 moles of Na, 2 moles of water, 2 moles of NaOH and 1 mole of H₂. In another example 3H₂ + N₂ => 2NH₃ there are 3 moles of H₂, 1 mole of N₂ and 2 moles of NH₃. The mole values can be multiples or fractions but if one mole value increases all the remaining mole values increase or decrease proportionally. For example:

Using the equation 2Na + 2H₂O => 2NaOH + H₂, one could multiply the equation by 2 giving 4Na + 4H₂O => 4NaOH + 2H₂. The equation shows balance but is not in standard form. If one multiplies the equation by ½ gives Na + H₂ => NaOH + ½H₂. Again, the equation shows balance but is not in standard form.

Standard form of equation also implies the equation conditions are at 0⁰C & 1atm pressure and 1 mole of any gas phase substance occupies 22.4 Liters volume. Such is the significance of converting given data to moles as all other substance mass (in moles) are proportional.

1st problem, 1.76 x 10²⁴ formula units of Na will react with water (usually read as an excess) to produce (?) grams of H₂.

1st write the equation followed by listing the givens below the respective formulas… That is…

Na + H₂O => NaOH + H₂,

Given: 1.76 x 10²⁴ atoms excess --------- ? grams

= 1.76 x 10²⁴atoms/6.023 x 10²³atoms/mole

= 2.922moles produces => 2.922moles H₂ (b/c coefficients of Na & H₂ are same)

Convert moles to grams => 2.922moles H₂ x 2.000 grams H₂/mole H₂

= 5.8443 grams H₂

2nd problem, 3.5 moles Na will react with H₂O (in excess) to produce (?) moles of NaOH.

Again, write equation and assign values to each formula unit in the equation.

Na + H₂O => NaOH + H₂,

Given: 3.5moles excess ? grams ----

Since coefficients of balanced std equation are equal …

3.5 moles Na produces => 3.5 moles NaOH

Convert moles to grams => 3.5 moles NaOH x 40 g Na/mole Na

= 140 grams NaOH

3rd problem, 2.75 x 10²⁵ molecules H₂O will react with (?) atoms of Na.

Same procedure, convert to moles, solve problem by ratios then convert to needed dimension at end of problem.

Na + H₂O => NaOH + H₂

Given: excess 2.75 x 10²⁵ molecules H₂O => ? atoms NaOH ----

Convert to moles => 2.75 x 10²⁵ molecules H₂O / 6.023 x 10²³ molecules H₂O/mole H₂O

= 45.658 moles H₂O => 45.658 moles NaOH (coefficients are equal)

Convert moles NaOH to grams NaOH => 45.658 moles NaOH x 40 grams NaOH/mole NaOH

= 1826.33 grams NaOH

Master the mole concept and you master a lot of chemistry! Good luck.

8 0

3 years ago

Mehtyl alcohol is called wood spirit. Its molecular formula is CH3OH. Calculate the number of moles that would contain 2.5*10^21

Phoenix [80]

The 2.5 x 10²¹ molecules of CH₃OH have 0.00415 moles.

<h3>What is the mole concept?</h3>

The Mole concept is used to express the amount of substance conveniently.

A mole is defined as the amount of substance that contains exactly 6.022 x 10²³ elementary particles of the given substance. Here, elementary particles refer to atoms, molecules, or ions.
This fixed number 6.022 x 10²³ is known as Avogadro Number and is denoted by $N_A$