<h3>
Answer:</h3>
3.01 × 10²⁵ molecules H₂O
<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>
- Using Dimensional Analysis
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
50.0 mol H₂O
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
<u />
= 3.011 × 10²⁵ molecules H₂O
<u>Step 4: Check</u>
<em>We are given 3 sig figs. Follow sig fig rules and round.</em>
3.011 × 10²⁵ molecules H₂O ≈ 3.01 × 10²⁵ molecules H₂O
Answer:
74.0 g/mol
Explanation:
Step 1: Write the generic neutralization reaction
HA + NaOH ⇒ NaA + H₂O
Step 2: Calculate the reacting moles of NaOH
At the equivalence point, 33.83 mL of 0.115 M NaOH react.
0.03383 L × 0.115 mol/L = 3.89 × 10⁻³ mol
Step 3: Calculate the moles of HA that completely react with 3.89 × 10⁻³ moles of NaOH
The molar ratio of HA to NaOH is 1:1. The reacting moles of HA is 1/1 × 3.89 × 10⁻³ mol = 3.89 × 10⁻³ mol.
Step 4: Calculate the molar mass of the acid
3.89 × 10⁻³ moles of HA have a mass of 0.288 g.
M = 0.288 g / 3.89 × 10⁻³ mol = 74.0 g/mol
Answer:
D- They use the exchange rate to convert one's Country's currency to another's
Explanation:
valance electrons that reside in the outermost shell of an atom in the highest energy level. They are important to atoms because the fewer valence electrons that the atom holds, it becomes less stable.
I take honors chemistry I hope this helps.
Answer:
That iron atom is oxidized. It loses two electrons.
Explanation:
Compare the formula of an iron atom and an iron(II) ion:
- Iron atom:
; - Iron(II) ion:
.
The superscript 
in the iron(II) ion is the only difference between the two formulas. This superscript indicates a charge of on each ion. Atoms and ions contain protons. In many cases, they also contain electrons. Each proton carries a positive charge of 
and each electron carries a charge of 
. Atoms are neutral for they contain an equal number of protons and electrons.
Protons are located at the center of atoms inside the nuclei. They cannot be gained or lost in chemical reactions. However, electrons are outside the nuclei and can be gained or lost. When an atom loses one or more electrons, it will carry more positive charge than negative charge. It will becomes a positive ion. Conversely, when an atom gains one or more electrons, it becomes a negative ion.
An iron atom will need to lose two electrons to become a positive iron(II) ion with a charge of on each ion. That is:
.
- Oxidation is Losing one or more electrons;
- Reduction is Gaining one or more electrons.
This definition can be written as the acronym OILRIG. (Khan Academy.)
In this case, each iron atom loses two electrons. Therefore the iron atoms here are oxidized.
