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3 years ago

H20 (s) -> h20 (g) endothermic or exothermic

Chemistry

1 answer:

noname [10]3 years ago

3 0

Answer:

Endothermic.

Explanation:

Hello there!

In this case, it is necessary to keep in mind that exothermic processes are characterized by the release of energy and the endothermic processes by the absorption of heat. In such a way, every process from solid to liquid or gas is endothermic as they require energy to separate the molecules and therefore turn out in the phase change. On the other hand, every process from gas to liquid or solid is exothermic as heat is released to rejoin the molecules and produce the phase change.

Therefore, since solid water molecules tend to be well-arranged, it is necessary to add heat to the system to produce the phase change until gas; in such a way, this process is endothermic as energy must be absorbed by the ice.

Best regards!

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Which resource produces the cleanest energy? coal gasoline oil wind

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Answer:

wind

Explanation:

wind is a natural and renewable resource

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C(S)+O2(g)-->CO2(g)

soldi70 [24.7K]

Answer: The correct answer is 1.18 g.

Explanation:

We are given a chemical equation:

$C(S)+O2(g)\rightarrow CO_2(g)$

We know that at STP conditions:

22.4L of volume is occupied by 1 mole of a gas.

So, 2.21L of carbon dioxide is occupied by = $\frac{1}{22.4L}\times 2.21L=0.0986mol$ of carbon dioxide gas.

By Stoichiometry of the above reaction:

1 mole of carbon dioxide gas is produced by 1 mole of carbon

So, 0.0986 moles of carbon dioxide is produced by = $\frac{1}{1}\times 0.0986=0.0986mol$ of carbon.

Now, to calculate the mass of carbon, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of carbon = 0.0986 mol

Molar mass of carbon = 12 g/mol

Putting values in above equation, we get:

$0.0986mol=\frac{\text{Mass of carbon}}{12g/mol}\\\\\text{Mass of carbon}=1.18g$

Hence, the correct answer is 1.18 g.

3 0

3 years ago

Read 2 more answers

Consider the reaction below for which K = 78.2 atm-1. A(g) + B(g) ↔ C(g) Assume that 0.386 mol C(g) is placed in the cylinder re

borishaifa [10]

Answer:

1.65 L

Explanation:

The equation for the reaction is given as:

A + B ⇄ C

where;

numbers of moles = 0.386 mol C (g)

Volume = 7.29 L

Molar concentration of C = $\frac{0.386}{7.29}$

= 0.053 M

A + B ⇄ C

Initial 0 0 0.530

Change +x +x - x

Equilibrium x x (0.0530 - x)

$K = \frac{[C]}{[A][B]}$

where

K is given as ; 78.2 atm-1.

So, we have:

$78.2=\frac{[0.0530-x]}{[x][x]}$

$78.2= \frac{(0.0530-x)}{(x^2)}$

$78.2x^2= 0.0530-x$

$78.2x^2+x-0.0530=0$

Using quadratic formula;

$\frac{-b+/-\sqrt{b^2-4ac} }{2a}$

where; a = 78.2 ; b = 1 ; c= - 0.0530

= $\frac{-b+\sqrt{b^2-4ac} }{2a}$ or $\frac{-b-\sqrt{b^2-4ac} }{2a}$

= $\frac{-(1)+\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$ or $\frac{-(1)-\sqrt{(1)^2-4(78.2)(-0.0530)} }{2(78.2)}$

= 0.0204 or -0.0332

Going by the positive value; we have:

x = 0.0204

[A] = 0.0204

[B] = 0.0204

[C] = 0.0530 - x

= 0.0530 - 0.0204

= 0.0326

Total number of moles at equilibrium = 0.0204 + 0.0204 + 0.0326

= 0.0734

Finally, we can calculate the volume of the cylinder at equilibrium using the ideal gas; PV =nRT

if we make V the subject of the formula; we have:

$V = \frac{nRT}{P}$

where;

P (pressure) = 1 atm

n (number of moles) = 0.0734 mole

R (rate constant) = 0.0821 L-atm/mol-K

T = 273.15 K (fixed constant temperature )

V (volume) = ???

$V=\frac{(0.0734*0.0821*273.15)}{(1.00)}$

V = 1.64604

V ≅ 1.65 L

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3 years ago

What happens to dissolving rate when you increase KE?

TEA [102]

In general, solubility increases with temperature. When you increase the temperature of a solvent, you increase the kinetic energy (or energy of movement) of the molecules, and this greater energy helps dissolve more of the solute molecules.

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The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, w

Valentin [98]

Answer:

Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.

Explanation:

Hydrogen bonding is a kind of intermolecular interaction that occurs when hydrogen is bonded to a highly electronegative atom.

Both water and alcohols exhibit hydrogen bonding. However, alcohols exhibit fewer hydrogen bonds than water.

As a result of this, the temperature of evaporation is much higher for water than for alcohol because hydrogen bonds hold water molecules more closely than alcohol molecules are held.

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3 years ago