It’s definitely magnesium but it may not be
Answer:
A.
Explanation:
I forgot butt im surely it is;-)
The given solution of Mn²⁺ is 0.60 mg/mL.
Hence mass of Mn²⁺ in 5 mL of solution = 0.60 mg/mL x 5 mL = 3 mg
Molar mass of Mn = 54.9 g/mol
Hence, moles of Mn²⁺ = 3 x 10⁻³ g / 54.9 g/mol = 5.46 x 10⁻⁵ mol
The balanced equation for the reaction is,
2Mn²⁺ + 5KIO₄ + 3H₂O → 2MnO₄⁻ + 5KIO₃ + 6H⁺
The stoichiometric ratio between Mn²⁺ and KIO₄ is 2 : 5
Hence, moles of KIO₄ reacted = 5.46 x 10⁻⁵ mol x (5 / 2)
= 13.65 x 10⁻⁵ mol
Molar mass of KIO₄ = 230 g/mol
Hence needed mass of KIO₄ = 13.65 x 10⁻⁵ mol x 230 g/mol
= 0.031395 g
= 31.395 mg
≈ 31.4 mg
Answer:
V = 11.21 L
Explanation:
Given data:
Volume of helium = ?
Number of moles = 0.500 mol
Temperature = 273.15 K
Pressure of gas = 1 atm
Solution:
Formula:
PV = nRT
R = general gas constant = 0.0821 atm.L/ mol.K
V = nRT/P
V = 0.500 mol × 0.0821 atm.L/ mol.K × 273.15 K / 1 atm
V = 11.21 L / 1
V = 11.21 L
