The first one is D hope it helps!
Answer:
29.41% of Calcium and 47.04% of Oxygen
Explanation:
The percent composition of an atom in a molecule is defined as 100 times the ratio between the mass of the atom and the mass of the molecule.
The mass of the molecule of the problem (Ore) is 46.28g. That means the percent composition of Calcium is:
13.61g / 46.28g * 100 = 29.41% of Calcium
And percent composition of Oxygen is:
21.77g / 46.28g * 100 = 47.04% of Oxygen
Answer:
The most effective strategy to control the spreading of some infections is through social distancing.
Explanation:
Since we don't have an effective treatment to stop the infection of some pathogens including the recent pandemic SARS-Cov 2 virus, it is imperative to prevent it from spreading
Answer:
c : 13%
Explanation:
Data Give:
Experimental density of vanadium = 6.9 g/cm³
percent error = ?
Solution:
Formula used to calculate % error
% error = [experimental value -accepted value/accepted value] x 100
The reported accepted density value for vanadium = 6.11 g/cm³
Put value in the above equation
% error = [ 6.9 - 6.11 / 6.11 ] x 100
% error = [ 0.79 / 6.11 ] x 100
% error = [ 0.129] x 100
% error = 12.9
Round to the 2 significant figure
% error = 13 %
So, option c is correct
Answer:
is the concentration of 
in the solution.
Explanation:
![Ni^{2+}(aq) + 3 en\rightleftharpoons [Ni(en)_3]^{2+}(aq)](https://tex.z-dn.net/?f=Ni%5E%7B2%2B%7D%28aq%29%20%2B%203%20en%5Crightleftharpoons%20%5BNi%28en%29_3%5D%5E%7B2%2B%7D%28aq%29)
Concentration of nickel ion = ![[Ni^{2+}]=x](https://tex.z-dn.net/?f=%5BNi%5E%7B2%2B%7D%5D%3Dx)
Concentration of nickel complex= ![[[Ni(en)_3]^{2+}]=\frac{0.16 mol}{2 L}=0.08 mol/L](https://tex.z-dn.net/?f=%5B%5BNi%28en%29_3%5D%5E%7B2%2B%7D%5D%3D%5Cfrac%7B0.16%20mol%7D%7B2%20L%7D%3D0.08%20mol%2FL)
Concentration of ethylenediamine = ![[en]=\frac{0.80 mol}{2 L}=0.40 mol/L](https://tex.z-dn.net/?f=%5Ben%5D%3D%5Cfrac%7B0.80%20mol%7D%7B2%20L%7D%3D0.40%20mol%2FL)
The formation constant of the complex = 
The expression of formation constant is given as:
![K_f=\frac{[[Ni(en)_3]^{2+}]}{[Ni^{2+}][en]^3}](https://tex.z-dn.net/?f=K_f%3D%5Cfrac%7B%5B%5BNi%28en%29_3%5D%5E%7B2%2B%7D%5D%7D%7B%5BNi%5E%7B2%2B%7D%5D%5Ben%5D%5E3%7D)
is the concentration of in the solution.
