Answer:
C) C₆H₁₂O₆.
Explanation:
- We can determine the molecular formula by calculating the molecular mass of different choices.
Molecular mass = ∑(no. of atoms * atomic mass).
A) CH₂O:
molecular mass = atomic mass of C + 2*atomic mass of H + atomic mass of O = (12.0 g/mol) + (2 * 1.0 g/mol) + (16.0 g/mol) = 30.0 g/mol.
B) C₃H₈O₃:
molecular mass = 3(atomic mass of C) + 8(atomic mass of H) + 3(atomic mass of O) = 3(12.0 g/mol) + 8(1.0 g/mol) + 3(16.0 g/mol) = 92.0 g/mol.
C) C₆H₁₂O₆:
molecular mass = 6(atomic mass of C) + 12(atomic mass of H) + 6(atomic mass of O) = 6(12.0 g/mol) + 12(1.0 g/mol) + 6(16.0 g/mol) = 180.0 g/mol.
D) C₈H₁₆O₈:
molecular mass = 8(atomic mass of C) + 16(atomic mass of H) + 8(atomic mass of O) = 8(12.0 g/mol) + 16(1.0 g/mol) + 8(16.0 g/mol) = 240.0 g/mol.
<em>So, the right choice is: C) C₆H₁₂O₆.</em>
<em></em>
Answer:
Concentration: 0.185M HX
Ka = 9.836x10⁻⁶
pKa = 5.01
Explanation:
A weak acid, HX, reacts with NaOH as follows:
HX + NaOH → NaX + H2O
<em>Where 1 mole of HX reacts with 1 mole of NaOH</em>
To solve this question we need to find the moles of NaOH at equivalence point (Were moles HX = Moles NaOH).
18.50mL = 0.01850L * (0.20mol / L) = 0.00370 moles NaOH = Moles HX
In 20.0mL = 0.0200L =
0.00370 moles HX / 0.0200L = 0.185M HX
The equilibrium of HX is:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
And Ka is defined as:
Ka = [H⁺] [X⁻] / [HX]
<em>Where [H⁺] = [X⁻] because comes from the same equilibrium</em>
As pH = 2.87, [H+] = 10^-pH = 1.349x10⁻³M
Replacing:
Ka = [H⁺] [H⁺] / [HX]
Ka = [1.349x10⁻³M]² / [0.185M]
Ka = 9.836x10⁻⁶
pKa = -log Ka
<h3>pKa = 5.01</h3>
Yes, that is true. in order for it to be a redox reaction, both oxidation and reduction must be occurring.
Liquid silver is less dense than solid silver, so the solid silver would sink
Answer:
The correct option is c) exothermic, negative.
Explanation:
Reactions that releases heat to the surroundings are called exothermic, and are characterized by negative entalpy (ΔH) values.
