B.)<span>A doctor would use technetium-99m because a short half-life indicates a quick measurement, and a geologist would use rubidium-87 because a longer half-life means that there is a longer time to measure old rock. </span>
Answer:
You cross multiply the valencies as shown
Explanation:
1. Al(OH)3
2. The valency of Calcium is 2- not 1- so,
CaO
Moles of Lithium phosphate : 0.495
<h3>Further explanation</h3>
Given
6 Li + Zn₃(PO₄)₂ ------- > 2 Li₃PO₄ + 3 Zn
Required
Moles of Lithium phosphate
Solution
moles of Zinc(Ar=65,38 g/mol) :
= mass : Ar
= 48.6 : 65.38
= 0.743
From equation, mol ratio of Zn : Li₃PO₄ = 3 : 2, so mol Li₃PO₄ :
= 2/3 x mol Zn
= 2/3 x 0.743
= 0.495
Answer:
6,04x10⁻³M
Explanation:
For the reaction:
Fe(s) + CuSO₄(aq) → Cu(s) + FeSO₄(aq)
The precipitate of Cu(s) weights 96,0 mg. In moles:
Moles of Cu(s):
0,096g×(1mol/63,546g) = 1,51x10⁻³ moles of Cu(s). If you see the balanced equation 1 mole of CuSO₄ produce 1 mole of Cu(s). That means moles of CuSO₄ are the same of Cu(s), <em>1,51x10⁻³ moles of CuSO₄</em>
As volume of the solution is 250 mL, 0,250L, the molar concentration of the original solution is:
1,51x10⁻³ moles of CuSO₄ / 0,250L = <em>6,04x10⁻³M</em>
I hope it helps!
