<h3>
Answer:</h3>
11.84 mol CoF₂
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
<u>Stoichiometry</u>
- Using Dimensional Analysis
- Analyzing Reactions RxN
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[RxN - Unbalanced] CoCl₂ + F₂ → CoF₂ + Cl₂
[RxN - Balanced] CoCl₂ + F₂ → CoF₂ + Cl₂
[Given] 11.84 moles CoCl₂
[Solve] moles CoF₂
<u>Step 2: Identify Conversions</u>
[RxN] 1 mol CoCl₂ → 1 mol CoF₂
<u>Step 3: Stoich</u>
- [DA] Set up:

- [DA] Multiply/Divide [Cancel out units]:

Answer:
So first thing to do in these types of problems is write out your chemical reaction and balance it:
Mg + O2 --> MgO
Then you need to start thinking about moles of Magnesium for moles of Magnesium Oxide. Based on the above equation 1 mole of Magnesium is needed to make one mole of Magnesium Oxide.
To get moles of magnesium you need to take the grams you started with (.418) and convert to moles by dividing by molecular weight of Mg (24.305), this gives you .0172 moles of Mg.
The theoretical yield would be the assumption that 100% of the magnesium will be converted into Magnesium Oxide, so you would get, based on the first equation, .0172 mol of MgO. Multiplying this by the molecular weight of MgO (24.305+16) gives us .693 g of MgO.
The percent yield is what you actually got in the experiment, and for this you subtract off the total mass from the crucible mass, or 27.374 - 26.687, which gives .66 g of MgO obtained.
Percent yield is acutal/theoretical, .66/.693, or 95.24%.
I'll let you do the same for the second trial, and average percent yield is just an average of the two trials percent yield.
Hope this helps.
Answer:
This question lacks options; the options are:
A) They moved more freely
B) They moved closer together.
C) The average speed increased.
D) The average kinetic energy increased
The answer is B
Explanation:
The water in the beaker is described to be in a liquid state of matter. Its temperature decreases from 50°C to 10°C when placed in a freezer by Kiley. This means that heat is gradually being lost as the liquid water undergoes freezing into a solid state.
When water in a liquid state is freezed, it's molecules, which were moving more freely begin to move closer together because the speed at which the particles in the liquid state moved has been reduced.
Answer:
2.32 m
Explanation:
So, according to definition of mole fraction:

Mole fraction = 0.176
Applying values as:


So,



Also, Molar mass of toluene = 92.14 g/mol
Thus,
The formula for the calculation of moles is shown below:


Also, 1 g = 0.001 kg
So,

Molality is defined as the moles of the solute present in 1 kg of the solvent.
It is represented by 'm'.
Thus,

<u>Molality of benzene = 2.32 m</u>
The electron configuration that represent an excited state for an atom of calcium is 2, 8, 7, 3.
Calcium atom has an atomic number of 20 and its electronic configuration is 2, 8, 8, 2. An atom is said to be in an excited state if it gains energy and move to an higher energy level. For the calcium atom given above, there are 20 electrons which are distributed into four shells. But in the excited state [option 3], one of the 8 electrons in the third shell gains energy and move to the fourth shell. Thus, the number of electrons in the third shell reduced by 1, while the number of electrons in the fourth shell increase by 1.