Answer:
Explanation:
The Rydberg equation gives the wavelength λ for the transitions:
where
R= the Rydberg constant (1.0974 ×10⁷ m⁻¹) and
Data:
λ = 657 nm
Calculation:
The chemical reaction involving sodium and oxygen as given in the reaction: 4Na + O2 → 2Na2O is a synthesis reaction.
<h3>What are chemical reactions?</h3>
Chemical reactions are changes which occur in the chemical composition of atoms of substances which results in the formation of new substances.
There are different types of chemical reactions such as:
- synthesis reaction
- displacement reaction
- double displacement reactions
A synthesis reaction is a reaction in which two or more substances combine to form a new product.
Therefore, the chemical reaction involving sodium and oxygen as given in the reaction: 4Na + O2 → 2Na2O is a synthesis reaction.
Learn more about chemical reactions at: brainly.com/question/11231920
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1) Start by standardizing the solution of NaOH by using the solution of H2SO4 whose concentration is known.
2) Equation:
2Na OH + H2SO4 --> Na2 SO4 + 2H2O
3) molar ratios
2 mol NaOH : 1 mol H2SO4
4) Number of moles of H2SO4 in 50.0 ml of 0.0782 M solution
M = n / V => n = M*V = 0.0782 M * 0.050 l = 0.00391 mol H2SO4
5) Number of moles of NaOH
2 moles NaOH / 1mol H2SO4 * 0.00391 mol H2SO4 = 0.00782 mol NaOH
6) Concentration of the solution of NaOH
M = n / V = 0.00782 mol / 0.0184 ml = 0.425 M
7) Standardize the solution of HCl
Chemical reaction:
NaOH + HCl --> NaCl + H2O
8) Molar ratios
1 mol NaOH : 1 mol HCl
9) Number of moles of NaOH in 27.5 ml
M = n / V => n = M * V = 0.425 M * 0.0275 l = 0.01169 moles NaOH
10) Number of moles of HCl
1 mol HCl / 1mol NaOH * 0.01169 mol NaOH = 0.01169 mol HCl
11) Concentration of the solution of HCl
M = n / V = 0.01169 mol / 0.100 l = 0.1169 M
Rounded to 3 significant figures = 0.117 M
Answers:
[NaOH] = 0.425 M
[HCl] = 0.117 M
The correct answer is: False.
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Water expands (gets larger/ is less dense in solid form than in liquid form) when it freezes).
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