What happens when kmno4 is heated

A sample of gas has a volume of 526 mL at 346 mmHg and 35.0°C. Determine the moles of gas.

Furkat [3]

Answer:

The moles of gas is 0.009474 moles.

Explanation:

Given that,

Volume = 526 mL

Pressure = 346 mmHg

Temperature = 35.0°C

We need to calculate the moles of gas

Using formula of ideal gas

$n=\dfrac{PV}{RT}$

Where, P = pressure

V = volume

R = gas constant

T = temperature

Put the value into the formula

$n=\dfrac{\dfrac{346}{760}\times0.526}{0.08206\times(35+273)}$

$n=0.009474\ moles$

Hence, The moles of gas is 0.009474 moles.

7 0

3 years ago

Drag each item to indicate whether it is related to Aristotle's or Ptolemy's model of the solar system, or to both. Some items m

Romashka-Z-Leto [24]

Answer:

Aristotle's Model :

geocentric

planets fixed on nested spheres

Ptolemy's model:

geocentric

planets fixed on epicycles

accurately predicted the positions of the planets

Explanation:

Let's begin by the fact both models are geocentric and make a brief explanation of them:

Aristotle's Model :

Aristotle built his model based on observations and philosophical assumptions, not on measurements or calculations, then he mistakenly thought the Earth was the center of the universe.

So, according to this model, the universe was spherical and finite, with the Earth immobile at its center, composed of the four fundamental elements (made up of spherical layers): ground, water, air and fire; and the Sun along with the fixed planets in their respective concentric spheres (also called nested spheres) revolving around the Earth.

Ptolemy's model:

Ptolemy's model of the universe was also geocentric, placing the Earth motionless in the center of the known universe and was the accepted model for a long time during the Middle Ages.

In this sense, ccording to Ptolemy's model of the universe our planet remains stationary while the other planets, the Moon and the Sun describe complicated orbits around it (called epicycles).

However, this model predicted with an acceptable accuracy for that time the motion of the known planets, until Copernicus appeared with the revolutionary Heliocentric model.

5 0

3 years ago

2 Which of the substances listed below are:

bulgar [2K]

Answer:

See explanation

Explanation:

Sea water = a mixture of different substances in water. If the water evaporates, some of those substances remain as salts. It's not a compound because it's a mixture of compounds and substances. An example of a compound is water ( because it has hydrogen atoms and an oxygen atom)

Calcium = Calcium is found on the periodic table so it cannot be a compound or mixture. It's a metallic element because we can find it on the left side of the periodic table, in group 2. It's an alkaline earth metal, what makes that calcium is a reactive metal.

Argon = Argon is found on the periodic table, so it can't be a mixture or compound. It is a non-metallic element. We can find it in group 18 on the periodic table. Argon is a noble gas, so non-metallic.

Water = a compound because its only made of 2 atoms : oxygen and hydrogen. Reasons why water is a compound and not a mixture are:

- The ormation of a compound is a chemical change which is followed by absorption of energy or evolution of energy, in case of water, electricity is required.

- Mixtures can be separated by physical separation techniques ,Water can not be separated into it its elements by physical separation techniques. But by the absorption of chemical energy.

Air = Mixture because it can be separated into different atoms, molecules,.. like oxygen, nitrogen etc. by the physical separation techniques (fractional distillation).

Carbon Monoxide = Carbon Monoxide is not found on the periodic table so it cannot be an element. It's made of 2 elements, this means caron monoxide is a compound. It's not a mixture since the elements cannot be separated by physical separating techniques.

Iron = Iron is found on the periodic table so it cannot be a compound or mixture. It's a metallic element because:

-High melting point

- Some metals form a dull oxide layer, this explains the shiny luster surface

- Electrical conductivity and thermal conductivity

Sodium chloride = NaCl cannot be found on the periodic table, so it isn't an element. It's a compound because it only has 2 atoms (elements). Those elements cannot be seperated by physical separating techniques, but would require electricity. So it's a compound.

Diamond = is a solid form of the element Carbon. It's an allotrope of carbon. They have the same physical state but in distinct form. Technically diamond is a non-metallic element. Since it's seen as carbon.

Brass = Brass is a mixture of the elements of copper and zinc. Those elements can be separated by physical techniques.

Copper = Copper is found on the periodic table so it cannot be a compound or mixture. It's a metallic element because:

-High melting point

- Some metals form a dull oxide layer, this explains the shiny luster surface

- Electrical conductivity and thermal conductivity

Dilute sulphuric acid = This is a mixture. Sulphuric acid is a compound but to dilute it's added in water, what is another compound. So it's a mixture of different compounds.

Sulphur = Can be found in the periodic table so it cannot be a mixture or compound. It's part of the metalloids, therefore, it can be concluded that sulfur is a non-metal. It belongs to the oxygen family.

Oil = Oil is a mixture of hydrocarbon compounds which varies in lengths.

Nitrogen = Nitrogen is found on the periodic table, so it can't be a mixture or compound. It can be found as a gas so it is a non-metallic element.

Ammonia = a compound of nitrogen and hydrogen with the formula NH3. Those elements cannot be separated with physical separating techniques.

5 0

3 years ago

3. Human activity can cause changes in one of the Earth's systems that lead to subsequent alterations in a different system. For

crimeas [40]

answer: Surface water in nearby areas can become polluted.

Explanation:

8 0

3 years ago

Why the earth is green

Svetlanka [38]

Answer:

the earth is green because the green part is the plants and tree.

4 0

3 years ago

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