Answer:
O.
Explanation:
- The element which is oxidized is the element that losses electrons and its oxidation state be more positive.
- The element which is reduced is the element that gain electrons and its oxidation state be more negative.
<em> O goes from 0 to -2, so, it is the element that is reduced.</em>
Number of moles = mass of Ni /molecular mass of Ni
mass of nickel = 86.4 g
molecular mass of nickel = 58.69
number of moles of Ni in 86.4 g
=86.4/58.69
=1.472 mol
(rounded to four significant figures instead of three because the first digit of the answer starts with a 1).
Answer: 1.32
Explanation:
First, we must obtain the molar mass of HBr. After that, we try to obtain the concentration of the hydrobromic acid from the formula n=CV since the volume of solution and mass of acid was provided. Recall that n=m/M. If the concentration of acid is thus obtained, we make use of the fact that the concentration of H+ in the acid is equal to the molar concentration of HBr to obtain the pH. The pH is the negative logarithm of the concentration we obtained in the initial step.
Answer:
%yield of NH₃ = 30%
Explanation:
Actual yield of NH₃ = 40.8g
Theoretical yield = ?
Equation of reaction
N₂ + 3H₂ → 2NH₃
Molar mass of NH₃ = 17g/mol
Molarmass of N = 14.00
2 molecules of N = 2 * 14.00 = 28g/mol
Number of moles = mass / molar mass
Mass = number of moles * molar mass
Mass = 1 * 28.00 = 28g of N₂ (the number of moles of N₂ from the equation is 1).
From the equation of reaction,
28g of N₂ produce (2 * 17)g of NH₃
28g of N₂ = 34g of NH₃
112g of N₂ = x g of NH₃
X = (112 * 34) / 28
X = 136g of NH₃
Theoretical yield = 136g of NH₃
% yield = (actual yield / theoretical yield) * 100
% yield = (40.8 / 136) * 100
% yield = 0.3 * 100
% yield = 30%
Answer:
Mass = 153.48 g
Explanation:
Given data:
Volume of solution = 2.50 L
Molarity = 0.48 M
Mass required = ?
Solution:
Molarity = number of moles / volume in litter
Number of moles = Molarity × volume in litter
Number of moles = 0.48 M × 2.50 L
Number of moles = 1.2 mol
Mass of HI:
Number of moles = mass/molar mass
Mass = Number of moles × molar mass
Mass = 1.2 mol × 127.9 g/mol
Mass = 153.48 g
