Answer:
What can cause excessive pressure on the high side of an active self-contained recovery device? A closed recovery tank inlet valve or excessive air or other non condensables in the recovery tank (either A or B) Portable refillable tanks or containers used to ship recovered refrigerants must meet what standard(s)?
Explanation:
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The product of replacement reaction of 2Fe + 3 CUSO4 yield 2Fe(SO4)3 + 3 Cu
during replacement reaction involve replacement of less reactive element in the reactivity series from its compound. Fe is more reactive in the reactivity series than cu therefore it Fe replaces cu from CUSO4
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
