Chemical reaction: Sr(OH)₂ + 2HNO₃ → Sr(NO₃)₂ + 2H₂O.
part A) m(Sr(OH)₂) = 21,78 g.
n(Sr(OH)₂) = m(Sr(OH)₂) ÷ M(Sr(OH)₂).
n(Sr(OH)₂) = 21,78 g ÷ 87,62 g/mol.
n(Sr(OH)₂) = 0,248 mol.
c(Sr(OH)₂) = n(Sr(OH)₂) ÷ V(Sr(OH)₂).
c(Sr(OH)₂) = 0,248 mol ÷ 0,075 L.
c(Sr(OH)₂) = 3,3 mol/L.
part B) V(Sr(OH)₂) = 34,21 mL = 0,03421 L.
n(Sr(OH)₂) = 0,03421 L · 3,3 mol/L = 0,112 mol.
From chemical reaction: n(Sr(OH)₂) : n(HNO₃) = 1 : 2.
n(HNO₃) = 0,225 mol.
V(HNO₃) = 0,225 mol ÷ 0,25 mol/L.
V(HNO₃) = 0,9 L = 900 ml.
Answer:
Element Helium have<u> 2 energy levels. </u>
Explanation:
<u>HELIUM -</u> With the symbol He and the atomic number 2, helium is a chemical element. It is a colorless , odorless, tasteless, non-toxic, inert, monatomic gas that is the first in the periodic table in the noble gas group. Of all the elements, its boiling point is the lowest.
At about 24 % of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined, it is present. In both the Sun and Jupiter, its abundance is identical to this. This is due to helium-4's very high nuclear binding energy (per nucleon) with respect to the next three elements following helium.
<u>Hence , the answer is 2 energy levels in Helium atom.</u>
Answer:
Each element consists of indivisible, minute particles called atoms.
All atoms of a given element are identical.
Atoms of different elements have different masses.
Explanation:
Mg3(PO4)2 - Mg²⁺ forms base
PO4³⁻ forms acid
Ma(OH)2 is a base(Y).
H3PO4 is an acid(X).
3Mg(OH)2 + 2H3PO4 ---> Mg3(PO4)2 + 3H2O
Answer:
fossils are rare bc most dead organisms get decayed by environmental change and decomposers,most fossils are parts of bones and mostly found indry areas like deserts