Answer:
9.8 × 10²⁴ molecules H₂O
General Formulas and Concepts:
<u>Atomic Structure</u>
- Reading a Periodic Table
 - Moles
 - Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
 
<u>Organic</u>
<u>Stoichiometry</u>
- Analyzing reaction rxn
 - Using Dimensional Analysis
 
Explanation:
<u>Step 1: Define</u>
[RxN - Unbalanced] CH₄ + O₂ → CO₂ + H₂O
[RxN - Balanced] CH₄ + 2O₂ → CO₂ + 2H₂O
[Given] 130 g CH₄
<u>Step 2: Identify Conversions</u>
Avogadro's Number
[RxN] 1 mol CH₄ → 2 mol H₂O
[PT] Molar Mass of C: 12.01 g/mol
[PT] Molar Mass of H: 1.01 g/mol
Molar Mass of CH₄: 12.01 + 4(1.01) = 16.05 g/mol
<u>Step 3: Stoichiometry</u>
- [DA] Set up conversion:                                                                                   

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

 
<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs.</em>
9.75526 × 10²⁴ molecules H₂O ≈ 9.8 × 10²⁴ molecules H₂O
 
        
             
        
        
        
Explanation:
Burning fossil fuels, changing land use, and using limestone to make concrete all transfer significant quantities of carbon into the atmosphere
 
        
             
        
        
        
One single covalent bond, hope this helps!
        
             
        
        
        
<h3>Answer:</h3>
                  162.43 g of FeCl₂
<h3>
Explanation:</h3>
Step 1: Calculate mass of Fe;
As,
                                    Density  =  Mass ÷ Volume
Or,
                                    Mass  =  Density × Volume
Where Volume is the volume of water displaced  =  10.4 mL
Putting values,
                                    Mass  =  7.86 g.mL⁻¹ × 10.4 mL
                                    Mass  =  81.744 g of Fe
Step 2: Calculate amount of FeCl₂;
The balance chemical equation is as follow,
                                 Fe  +  2 HCl   →    FeCl₂  +  H₂ ↑
According to this equation,
        55.85 g (1 mol) Fe produced  =  110.98 g (1 mol) of FeCl₂
So,
                81.744 g Fe will produce  =  X g of FeCl₂
Solving for X,
                      X  =  (81.744 g × 110.98 g) ÷ 55.85 g
                      X  =  162.43 g of FeCl₂
 
        
             
        
        
        
Answer:
In the criss-cross method, the numerical value of the ion charge of the two atoms are crossed over, which becomes the subscript of the other ion. Using this technique, we will write the chemical formula of the given compounds.
Criss cross the absolute values to give Al2O3. To find the formula for magnesium oxide:- The oxidation number of Mg is +2 and oxygen is -2. Criss cross the absolute values to give Mg2O2In this example there is a common factor of 2 so divide by 2 to give MgO.