For the first one.. the Reactant side is Zn+2HCl produces Zncl2 and H2... and it is balanced too
Answer is: silicon isotope with mass number 28 has highest relative abundance, this isotope is the most common of these three isotopes.
Ar₁(Si) = 28; the average atomic mass of isotope ²⁸Si.
Ar₂(Si) =29; the average atomic mass of isotope ²⁹Si.
Ar₃(Si) =30; the average atomic mass of isotope ³⁰Si.
Silicon (Si) is composed of three stable isotopes, ₂₈Si (92.23%), ₂₉Si (4.67%) and ₃₀Si (3.10%).
ω₁(Si) = 92.23%; mass percentage of isotope ²⁸Si.
ω₂(Si) = 4.67%; mass percentage of isotope ²⁹Si.
ω₃(Si) = 3.10%; mass percentage of isotope ³⁰Si.
Ar(Si) = 28.086 amu; average atomic mass of silicon.
Ar(Si) = Ar₁(Si) · ω₁(B) + Ar₂(Si) · ω₂(Si) + Ar₃(Si) · ω₃(Si).
28,086 = 28 · 0.9223 + 29 · 0.0467 + 30 · 0.031.
I believe the answer is D.
Answer:
Explanation:
Number of moles of CuCl2 initially present = volume * molar concentration
= 0.134 * 8
= 1.072 mol.
Molar mass of CuCl2 = 63.5 + (2*35.5)
= 134.5 g/mol
Mass of CuCl2 = molar mass * number of moles
= 134.5 * 1.072
= 144.184 g
Mass of CuCl2 in 48 ml = 5.89 g in 48 ml
Volume = 5.89 * (48/144.184)
= 1.96 ml.