The model<span> of the </span>atom<span> has dramatically </span>changed<span> over many many years.We learn </span>atoms<span> make up different substances and are the smallest particles of matter. which can have subatomic particles that are very small portions of matter.at first scientist only thought there were electrons which are negatively charged.</span>
Answer:
Mole fraction H₂O → 0.72
Mole fraction C₂H₅OH → 0.28
Explanation:
By the mass of the two elements in the solution, we determine the moles of each:
25 g . 1 mol/ 18g = 1.39 moles of water (solute)
25 g . 1 mol / 46 g = 0.543 moles of ethanol (solvent)
Mole fraction solute = Moles of solute / Total moles
Mole fraction solvent = Moles of solvent / Total moles
Total moles = Moles of solute + Moles of solvent
1.39 moles of solute + 0.543 moles of solvent = 1.933 moles → Total moles
Mole fraction H₂O = 1.39 / 1.933 → 0.72
Mole fraction C₂H₅OH= 0.543 / 1.933 → 0.28
Remember that sum of mole fractions = 1
Answer:
1) The value of Kc:
C. remains the same.
2) The value of Qc:
A. is greater than Kc.
3) The reaction must:
B. run in the reverse direction to restablish equilibrium.
4) The concentration of N2 will:
B. decrease.
Explanation:
Hello,
In this case, by means of the Le Chatelier's principle which is based on the shift a chemical reaction could have under some modifications, we have:
1) The value of Kc:
C. remains the same, since it just depend the reaction's thermodynamics as it is computed via:

2) The value of Qc:
A. is greater than Kc, since the reaction quotient is:
![Qc=\frac{[N_2][H_2]^3}{[NH_3]^2}](https://tex.z-dn.net/?f=Qc%3D%5Cfrac%7B%5BN_2%5D%5BH_2%5D%5E3%7D%7B%5BNH_3%5D%5E2%7D)
Thus, the lower the concentration of ammonia, the higher Qc, making Qc>Kc.
3) The reaction must:
B. run in the reverse direction to restablish equilibrium, since ammonia was withdrawn and should be regenerated to reach the equilibrium.
4) The concentration of N2 will:
B. decrease, since less reactant is forming the products.
Best regards.
Answer:
3.01 × 10²³ atoms Ne
General Formulas and Concepts:
<u>Atomic Structure</u>
- Reading a Periodic Tables
- Moles
<u>Stoichiometry</u>
- Using Dimensional Analysis
Explanation:
<u>Step 1: Define</u>
<em>Identify</em>
[Given] 10.1 g Ne
[Solve] atoms Ne
<u>Step 2: Identify Conversions</u>
Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
[PT] Molar Mass of Ne: 20.18 g/mol\
<u>Step 3: Convert</u>
- [DA] Set up:

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

<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 3 sig figs.</em>
3.01398 × 10²³ atoms Ne ≈ 3.01 × 10²³ atoms Ne
Answer:
Total percent of magnesium in sample = 25.5%
Explanation:
Given:
Mass of magnesium = 24 gram
Mass of chlorine = 70 gram
Find:
Total percent of magnesium in sample = ?
Computation:
Total mass of sample = Mass of magnesium + Mass of chlorine
Total mass of sample = 24 gram + 70 gram
Total mass of sample = 94 gram
Total percent of magnesium in sample = [Mass of magnesium / Total mass of sample]100
Total percent of magnesium in sample = [24/94]100
Total percent of magnesium in sample = [0.255]100
Total percent of magnesium in sample = 25.5%