The empirical formula of a compound is determined to be CH2O, and its molecular mass is found to be 90.087 g/mol. Determine the molecular formula of the compound, showing your solution.
Answer: This is actually quite simple, first we have to calculate the molar mass of empirical unit. Therefore we have 12+2*1+16 = 30. Then we solve 90/30 = 3. Finally we end up with 3*(CH2O) --> C3H6O3.
I hope it helps, Regards.
Answer:
In order to answer the question, we convert the measurements given to a common base unit. For this case, we use seconds.
A) 0.02 seconds
B) 0.02 teraseconds x (10^12 s / 1 terasecond) = 2x10^10 seconds
C) 2,500 milliseconds x (1 s / 1000 ms) = 2.5 seconds
D) 25,000 nanoseconds x (1 x 10^-9 s / 1 nanosecond) = 2.5 x 10^-5 seconds
So ,The correct answer is option " D "
Answer:
11.31g NaClO₂
Explanation:
<em> Is given 250mL of a 1.60M chlorous acid HClO2 solution. Ka is 1.110x10⁻². What mass of NaClO₂ should the student dissolve in the HClO2 solution to turn it into a buffer with pH =1.45? </em>
It is possible to answer this question using Henderson-Hasselbalch equation:
pH = pKa + log₁₀ [A⁻] / [HA]
<em>Where pKa is -log Ka = 1.9547; [A⁻] is the concentration of the conjugate base (NaClO₂), [HA] the concentration of the weak acid</em>
You can change the concentration of the substance if you write the moles of the substances:
[Moles HClO₂] = 250mL = 0.25L×(1.60mol /L) = <em>0.40 moles HClO₂</em>
Replacing in H-H expression, as the pH you want is 1.45:
1.45 = 1.9547 + log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]
-0.5047 = log₁₀ [Moles NaClO₂] / [0.40 moles HClO₂]
<em>0.3128 = </em>[Moles NaClO₂] / [0.40 moles HClO₂]
0.1251 = Moles NaClO₂
As molar mass of NaClO₂ is 90.44g/mol, mass of 0.1251 moles of NaClO₂ is:
0.1251 moles NaClO₂ ₓ (90.44g / mol) =
<h3>11.31g NaClO₂</h3>
Explanation:
The valence electrons within an atom is the number of electrons in its outermost shell.
These electrons are used by an atom to react with one another. They determine the extent to which an atom is ready to combine either by losing, gaining or sharing these electrons.
- Every atom desires to have a completely filled outermost shell.
- Only the elements in group 8 have a complete octet.
- The need to attain stability is driven by the number of electrons in their valence shell.
- Therefore, some atoms are very reactive.
- Those needing one electrons to complete their octet and also those that must lose one electron are very reactive.
