Answer:
The mass percent of potassium is 39%
Option C is correct
Explanation:
Step 1: Data given
Atomic mass of K = 39.10 g/mol
Atomic mass of H = 1.01 g/mol
Atomic mass of C = 12.01 g/mol
Atomic mass of O = 16.0 g/mol
Step 2: Calculate molar mass of KHCO3
Molar mass KHCO3 = 39.10 + 12.01 + 1.01 + 3*16.0
Molar mass KHCO3 = 100.12 g/mol
Step 3: Calculate mass percent of potassium (K)
%K = (atomic mass of K / molar mass of KHCO3) * 100%
%K = (39.10 / 100.12) * 100%
%K = 39.05 %
The mass percent of potassium is 39%
Option C is correct
The balanced half reactions are
4 Fe2+ ====> 4 Fe3+ + 4 e-
<span>MnO42- + 8 H+ + 4 e- ===> Mn2+ + 4 H2O
The net ionic equation is
4 Fe2+ + </span>MnO42- + 8 H+ ===> 4 Fe3+ + Mn2+ + 4 H2O<span />
So we know that the equation for density is:
![D=\frac{m}{V}](https://tex.z-dn.net/?f=%20D%3D%5Cfrac%7Bm%7D%7BV%7D%20)
where D is the density, m is the mass in grams, and V is the volume in mL.
So since we know two of the variables, mass and density, we can solve for the volume:
![\frac{1.020g}{mL}=\frac{147g}{V}](https://tex.z-dn.net/?f=%20%5Cfrac%7B1.020g%7D%7BmL%7D%3D%5Cfrac%7B147g%7D%7BV%7D%20)
![V=\frac{147g}{\frac{1.020g}{mL}}](https://tex.z-dn.net/?f=%20V%3D%5Cfrac%7B147g%7D%7B%5Cfrac%7B1.020g%7D%7BmL%7D%7D%20)
![V=144.12mL](https://tex.z-dn.net/?f=%20V%3D144.12mL%20)
Therefore, the volume of this urine sample is 144.12mL.
Answer:
True
Explanation:
The speed that electromagnetic waves will travel within any medium is the same as those without a medium. The speed of electromagnetic wave is a constant and does not depend on the material of the medium.
- Electromagnetic waves are waves that do not require a material medium for their propagation.
- They are able to pass through vacuums and mediums with particles at constant speed.
- It is mechanical waves whose speed is medium dependent.
- Mechanical waves have varying speed based on the mediums they move through.