Answer:
a. Boron trifluoride
b. Propane
c. Dinitrogen pentoxide
d. Carbon Dioxide
e. Silicon Octafluroride?
Answer:
only columns
Explanation:
All atoms of elements present in same group or column having same number of valance electrons. Thus the elements in same group having same properties.
For example:
Consider the second group. It consist of alkaline earth metals. There are six elements in second group. Beryllium, magnesium, calcium, strontium, barium and radium.
All have two valance electrons.
Electronic configuration of Beryllium:
Be = [He] 2s²
Electronic configuration of magnesium.
Mg = [Ne] 3s²
Electronic configuration of calcium.
Ca = [Ar] 4s²
Electronic configuration of strontium.
Sr = [Kr] 5s²
Electronic configuration of barium.
Ba = [Xe] 6s²
Electronic configuration of radium.
Ra = [ Rn] 7s²
They are present in group two and have same number of valance electrons (two valance electrons) and show similar reactivity.
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
MgO + H₂O → Mg(OH)₂
CaO + H₂O → Ca(OH)₂
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Answer:
Explanation:
<u>The alkaline solution: </u>
40 ml of 0.1 M KOH
<u>The acid solution: </u>
30 ml of 0.1 M HCl
The neutralization reaction:
For 1 mol of HCl, 1 mol of KOH is consumed. If 0.003 mol of HCl are added, 0.003 mol of KOH reacted.
After titration:
Concentration (don't forget to add the volumes)
Calcualtion of the pOH:
![pOH=-log([OH^-])=-log(0.0143)=1.84](https://tex.z-dn.net/?f=pOH%3D-log%28%5BOH%5E-%5D%29%3D-log%280.0143%29%3D1.84)
For the pH:
Answer:
B.
Explanation:
One mole is the amount of substance that contain the Avogadro number which is equal to 6.022×10^23 atom, molecules or ions.
Equality is for something to be equal to another thing.
