B,Si,Ge,As,Sb,Te, and At are all the metalloids on the periodic table of elements.
Just add up the molar masses of each element.
Molar mass of C: 12.011 g/mol
The equation says C20, which means there are 20 carbon atoms in each molecule of Vitamin A. So, we multiply 12.011 by 20 to get 240.22 g/mol carbon.
Molar mass of H: 1.0079 g/mol
The equation says C30, which means there are 30 hydrogen atoms in each molecule of Vitamin A. So, we multiply 1.0079 by 30 to get 30.237 g/mol hydrogen.
Molar mass of O: 15.999 g/mol
The equation says O without a number, which means there is only one oxygen atom in each molecule of Vitamin A. So, we leave O at 15.999 g/mol.
Then, just add it up:
240.22 g/mol C + 30.237 g/mol H + 15.999 g/mol O = 286.456 g/mol C20H30O
So, the molar mass of Vitamin A, C20H30O, is approximately 286.5 g/mol.
Answer:
Explanation:
193.02 times 9.55 it's going to be 1843.341
9.55= 191.20 milli
This statement is: False
Boiling is vaporization that occurs both below and at the surface of the liquid.
However, evaporation happens at the surface of the substance.
So, if you need to correct this statement, the correction would be:
Sublimation and evaporation happen at the surface of the substance.
Answer: the percent by mass of potassium nitrate is 13.3%
Explanation:
<u>1) Data:</u>
- Mass of solute, m₁ = 45.0 g
- Volume of solvent, V₂ = 295 ml
- density of water, d₂ = 0.997 g/ml
<u>2) Formulae</u>:
- Percent by mass, % = (mass of solute / mass of solution) × 100
- Density, d = mass / volume
<u>3) Solution</u>:
- d = mass / volume ⇒ m₂ = d₂ × V₂ = 0.997 g/ml × 295 ml = 294. g
- mass of solution = m₁ + m₂ = 45.0g + 294. g = 339. g
- % = (45.0 g / 339. g) × 100 = 13.3 %
- The answer has to be reported with 3 significant figures.
