Large-scale environmental catastrophes ______

What is evaporation? Describe what happens at the molecular level during evaporation.

jasenka [17]

Evaporation happens when atoms or molecules escape from the liquid and turn into a vapor. Not all of the molecules in a liquid have the same energy. Sometimes a liquid can be sitting in one place (maybe a puddle) and its molecules will become a gas. That's the process called evaporation. It can happen when liquids are cold or when they are warm. It happens more often with warmer liquids. You probably remember that when matter has a higher temperature, the molecules have a higher energy. When the energy in specific molecules reaches a certain level, they can have a phase change. Evaporation is all about the energy in individual molecules, not about the average energy of a system. The average energy can be low and the evaporation still continues.

6 0

3 years ago

_______ law states the volume of a definite quantity of dry gas is inversely proportional to the pressure, provided the temperat

nasty-shy [4]

Boyles law --i hope this helps

5 0

3 years ago

3Fe+4H2O(yields) Fe3O4+4H2. What is the mole ratio of Fe3O4 to Fe?

WINSTONCH [101]

Answer: The correct answer is Option A.

Explanation:

Mole ratio is defined as the ratio between the stoichiometric coefficients of the molecules present in the chemical reaction.

For the given balanced chemical equation:

$3Fe+4H_2O\rightarrow Fe_3O_4+4H_2$

By Stoichiometry of the reaction:

3 moles of iron metal reacts with 4 moles of water to produce 1 mole of iron oxide and 4 moles of hydrogen gas.

The mole ratio of $Fe_3O_4:Fe=1:3$

Hence, the correct answer is Option A.

7 0

3 years ago

Read 2 more answers

Explain why the first ionisation energy of krypton is greater then the first ionisation energy of bromine

MrMuchimi

Answer:

Kr has one more electron than br and so, the nuclear charge increase, which means the nuclear attraction between the nucleus and outer most electron will increase and so will be harder to remove the electron from Kr than Br, so Kr has higher 1st ionisation.

Mark me brainliest!

God bless!

3 0

3 years ago

Oxygen gas can be prepared by heating potassium chlorate according to the following equation:2KClO3(s)Arrow.gif2KCl(s) + 3O2(g)T

Eduardwww [97]

Answer:

Moles of potassium chlorate reacted = 0.2529 moles

The amount of oxygen gas collected will be 12.8675 g

Explanation:

(a)

We are given:

Vapor pressure of water = 17.5 mmHg

Total vapor pressure = 748 mmHg

Vapor pressure of Oxygen gas = Total vapor pressure - Vapor pressure of water = (748 - 17.5) mmHg = 730.5 mmHg

To calculate the amount of Oxygen gas collected, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 730.5 mmHg

V = Volume of the gas = 9.49 L

T = Temperature of the gas = $20^oC=[20+273]K=293K$

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of oxygen gas = ?

Putting values in above equation, we get:

$730.5mmHg\times 9.49L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 293K\\\\n=\frac{730.5\times 9.49}{62.3637\times 293}=0.3794mol$

According to the reaction shown below as:-

$2KClO_3(s)\rightarrow 2KCl(s) +3O_2(g)$

3 moles of oxygen gas are produced when 2 moles of potassium chlorate undergoes reaction.

So,

0.3794 mol of oxygen gas are produced when $\frac{2}{3}\times 0.3794$ moles of potassium chlorate undergoes reaction.

Moles of potassium chlorate reacted = 0.2529 moles

(b)

We are given:

Vapor pressure of water = 17.5 mmHg

Total vapor pressure = 753 mmHg

Vapor pressure of Oxygen gas = Total vapor pressure - Vapor pressure of water = (753 - 17.5) mmHg = 735.5 mmHg

To calculate the amount of Oxygen gas collected, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 735.5 mmHg

V = Volume of the gas = 9.99 L

T = Temperature of the gas = $20^oC=[20+273]K=293K$

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

n = number of moles of oxygen gas = ?

Putting values in above equation, we get:

$735.5mmHg\times 9.99L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 293K\\\\n=\frac{735.5\times 9.99}{62.3637\times 293}=0.40211mol$

Moles of Oxygen gas = 0.40211 moles

Molar mass of Oxygen gas = 32 g/mol

Putting values in above equation, we get:

$0.037mol=\frac{\text{Mass of Oxygen gas}}{2g/mol}\\\\\text{Mass of Oxygen gas}=(0.40211mol\times 32g/mol)=12.8675g$

Hence, the amount of oxygen gas collected will be 12.8675 g

5 0

3 years ago

Large-scale environmental catastrophes _______.