Answer:
Lake and River pollution?
Explanation:
The anode is the negative electrode and so will be donating electrons to assist in this chemical reaction occuring. All reactions accept electrons as reactants. The key issue is the reduction potential Eo (+1.8V). This is greatest for the reaction:
Co3+ + e -> Co2+
Therefore this reaction has the greatest tendency to occur.
Answer:
69.8 kilo Pasacl is the pressure of the hydrogen gas.
Explanation:

Pressure at which hydrogen gas collected = p = 101.2 kilo Pascals
Vapor pressure water =
= 31.4 kilo Pascals
The pressure of hydrogen gas = P
The pressure at which gas was collected was sum of vapor pressure of water and hydrogen gas.


69.8 kilo Pasacl is the pressure of the hydrogen gas.
Answer:
1.26 M
Explanation:
The ion nitrate is NO₃⁻ and the Barium is from group 2 so it forms the ion Ba²⁺, so the barium nitrate has the formula: Ba(NO₃)₂. The molar masses are: Ba: 137 g/mol, N = 14 g/mol, O = 16 g/mol, so the molar mass of barium nitrate is:
137 + 2x(14 + 3x16) = 199 g/mol
The number of moles is the mass divided by the molar mass, so:
n = 25.1/199 = 0.126 mol of Ba(NO₃)₂
In 1 mol of the salt, there are 2 moles of NO₃⁻, so the number of moles of nitrate is 0.252 mol. Nitrates formed with ammonium (that can react when the solid dissolves) and with elements from group 1 and 2 are completely soluble in water. So, the moles of nitrate will remain 0.252 mol.
The molarity is the number of moles divided by the volume (0.2 L):
[NO₃⁻]= 0.252/0.2 = 1.26 M