If you were asked to convert 4.2 × 1022 atoms of aluminum to moles, which of the following should you use for the conversion?

What is the difference between atomic mass, relative atomic mass and average atomic mass

vesna_86 [32]

$\bold{\huge{\underline{\purple{ Answer }}}}$

Difference between Atomic mass, relative atomic mass and average atomic mass :-

<h3>Atomic Mass :-</h3>

Atomic mass is the mass of neutrons and protons present in the nucleus of an atom .
It is always calculated for a single element and having direct value
For isotopes also, the atomic mass is calculated separately . Example :- Carbon 12 , carbon 13 and carbon 14 have different atomic mass. 
The SI unit of Atomic mass is " u" and "amu"

<h3>Relative Atomic mass :-</h3>

Relative atomic mass is mean mass of the atoms of an element which is compared to the 1/12th mass of carbon - 12 .
Carbon - 12 is taken as a relative when we calculate the relative atomic mass of any element
For calculating relative atomic mass, we need to know the masses, percentage and abundance of all types of elements
Relative atomic mass is a dimension less quantity

<h3>Average Atomic Mass :-</h3>

Average atomic mass is the average mass of an atoms of a particular element by considering it's isotopes
While we calculate average atomic mass is a standardized number. Whereas, Average atomic mass sometimes varies geologically .
It also includes percentage, abundance and masses of given element .
In average atomic mass, We do not compare mean value with the 1/12 mass of carbon - 12
The unit of Average atomic mass is "Amu" or " u " .

5 0

2 years ago

A car travels 10km in 10 min so what is the average

ipn [44]

Average speed in km/h:

S = D/T

T = 10/60 hrs
= 0.1667

S = 10 / 0.1667
= 59.988 km/h

4 0

2 years ago

How many joules are needed to warm 65.6 grams of water from 14ºC to 22.5ºC?

Ahat [919]

Answer:

2334.1136 Joules

Explanation:

Q= 65.6 g (4.186)(8.5)

If it's suppose to be in kilograms, the answer will be 2.3341136 Joules.

7 0

2 years ago

In which level of organization would the roots of a plant most likely be classified. Make sure to explain

Nookie1986 [14]

Answer:

jsjsososjahshbsjakaokwwj

6 0

2 years ago

S8 + 24 F2 ⟶ 8 SF6

Arturiano [62]

Answer:

Theoretical Yield of SF₆ = 2.01 moles

Explanation: If you understand and can apply the methodology below, you will find it applies to ALL chemical reaction stoichiometry problems based on the balanced standard equation; i.e., balanced to smallest whole number coefficients.

Solution 1:

Rule => Convert given mass values to moles, solve problem using coefficient ratios. Finish by converting moles to the objective dimensions.

Given S₈ + 24F₂ => 8SF₆

425g 229g ?

= 425g/256g/mol. = 226g/38g/mol.

= 1.66 moles S₈ = 6.03 moles F₂ <= Limiting Reactant

Determining Limiting Reactant => Divide moles each reactant by their respective coefficient; the smaller value will always be the limiting reactant.

S₈ = 1.66/1 = 1.66

F₂ = 6.03/24 = 0.25 => F₂ is the limiting reactant

Determining Theoretical Yield:

Note: When working problem do not use the division ratio results for determining limiting reactant. Use the moles F₂ calculated from 229 grams F₂ => 6.03 moles F₂. The division procedure to define the smaller value and limiting reactant is just a quick way to find which reactant controls the extent of reaction.

Given S₈ + 24F₂ => 8SF₆

425g 229g ?

= 425g/256g/mol. = 226g/38g/mol.

= 1.66 moles S₈ = 6.03 moles F₂ <= Limiting Reactant

Max #moles SF₆ produced from 6.03 moles F₂ and an excess S₈

Since coefficient values represent moles, the reaction ratio for the above reaction is 24 moles F₂ to 8 moles SF₆. Such implies that the moles of SF₆ (theoretical) calculated from 6.03 moles of F₂ must be a number less than the 6.03 moles F₂ given. This can be calculated by using a ratio of equation coefficients between 24F₂ and 8SF₆ to make the outcome smaller than 6.03. That is,

moles SF₆ = 8/24 x 6.03 moles = 2.01 moles SF₆ (=> theoretical yield)

S₈ + 24F₂ => 8SF₆

moles SF₆ = 8/24(6.03) moles = 2.01 moles

You would NOT want to use 24/8(6.03) = 18.1 moles which is a value >> 6.03.

This analysis works for all reaction stoichiometry problems.

Convert to moles => divide by coefficients for LR => solve by mole mole ratios from balanced reaction and moles of given.

____________________

Here's another example just for grins ...

C₂H₆O + 3O₂ => 2CO₂ + 3H₂O

Given: 253g 307g ? ?

a. Determine Limiting Reactant

b. Determine mass in grams of CO₂ & H₂O produced

Limiting Reactant

moles C₂H₆O = 253g/46g/mol = 5.5 moles => 5.5/1 = 5.5

moles O₂ = 307g/32g/mol = 9.6 moles => 9.6/24 = 0.4 ∴ O₂ is L.R.

But the problem is worked using the mole values; NOT the number results used to ID the limiting reactant.

C₂H₆O + 3O₂ => 2CO₂ + 3H₂O

------------ 9.6 mole (L.R.) ? ?

mole yield CO₂ = 2/3(9.6)mole = 6.4 mole (CO₂ coefficient < O₂ coefficient)

mole yield H₂O = 9.6mole = 9.6mole (coefficients O₂ & CO₂ are same.)

mole used C₂H₆O = 1/3(9.6)mole = 3.2 mole (coefficient C₂H₆O < coefficient O₂)

For grams => moles x formula weight (g/mole)

7 0

2 years ago