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3 years ago

Wich value gives the number of particles in 1 mol of a substance

Chemistry

2 answers:

juin [17]3 years ago

5 0

Answer: 6.022x10²³ (Avogadro's Number)

Explanation: The number of particles in 1 mole of a substance is determined by the Avogadro's Number.

exis [7]3 years ago

4 0

6.02x10 the power of 23 ( Avogadro formula)

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A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heatin

torisob [31]

Answer:

I disagree with the student's claim

Explanation:

From basic chemistry, the rate of chemical reaction increases with an increased surface area.

This simply means that a powdered substance will react faster than a small pellet of the same substance.

Let us break this down further. The pellet has a smaller exposed surface per grain to the solvent, here is how. Imagine the powdered substance bunched up together to make the small pellet, grains at the center of the pellet is blocked by other grains around it, and will take time before it comes in contact with the solvent. For the powdered grains, each grain has a surface independently exposed to the solvent and can easily come in contact with the solvent, taking less time to react with the solvent.

Technically, a powdered substance has more exposed surface area and logically will take a shorter time for the reaction to be complete.

4 0

3 years ago

You have 0.672 L of 4.78 M aqueous AlCl3 solution in a glass. If you gently heat the solution until only 0.380 L is left, what i

vlada-n [284]

Answer:

8.45 M

Explanation:

To solve this problem we need to keep in mind the definition of molarity:

Molarity = moles / volume

First we calculate the moles of AlCl₃ in 0.672 L of a 4.78 M solution:

Moles = Molarity * volume

Moles = 4.78 M * 0.672 L

Moles = 3.212 moles

Then we calculate the new molarity of the AlCl₃ solution using that number of moles, which remains the same throughout the evaporation process:

New Molarity = 3.212 moles / 0.380 L

New Molarity = 8.45 M

3 0

2 years ago

You are given an unknown mixture containing NaCl and NaHCO3. When you carry out the heating exactly as described in part A, only

SOVA2 [1]

Answer:

1.52g NaHCO3 were in the original mixture.

Mass percent: 64.1%

Explanation:

When NaHCO3 heats it descomposition occurs as follows:

2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g).

The loss in mass is because of the evaporization of CO2 and H2O. As both are in the same porportion, its molar mass is the sum of both compounds (44g/mol + 18g/mol = 62g/mol)

Loss in mass: 74.80g - 74.24g = 0.56g.

In moles:

0.56g * (1mol / 62g) = 0.00903 moles of gas.

As 1 mole of the gases comes from 2 moles of NaHCO3:

Moles NaHCO3:

0.00903 moles of gas * (2 moles NaHCO3 / 1 mole gas) = 0.018 moles NaHCO3.

In grams (Molar mass NaHCO3: 84g/mol):

0.018 moles NaHCO3 * (84g / mol) = 1.52g NaHCO3 were in the original mixture.

The mass of the mixture was:

74.80g - 72.428g = 2.372g

That means mass percent of NaHCO3 is:

(1.52g / 2.372g) * 100 = 64.1%

7 0

3 years ago

Which element has the highest electronegativity?

Flauer [41]

Fluorine has the highest electronegativity charge. Its electronegativity charge is 4.0

6 0

2 years ago

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Which statement is correct about the law of conversation of energy

Elden [556K]

Answer:

Energy is transferred when atoms are rearranged.

Explanation:

6 0

3 years ago