Answer: Option (4) is the correct answer.
Explanation:
It is known that density is mass divided by volume.
Mathematically, Density =
Since, density is directly proportional to mass. So, more is the mass of an element more will be its density.
Mass of magnesium is 24.305 g/mol.
Mass of barium is 137.327 g/mol.
Mass of beryllium is 9.012 g/mol
Mass of radium is 226 g/mol.
Hence, radium has more mass therefore it will have the greatest density at STP.
Answer:
D) empirical formula is: C₃P₂O₈
Explanation:
Given:
Mass % Calcium (Ca) = 38.7%
Mass % Phosphorus (P) = 19.9%
Mass % oxygen (O) = 41.2 %
This implies that for a 100 g sample of the unknown compound:
Mass Ca = 38.7 g
Mass P = 19.9 g
Mass O = 41.2 g
Step 1: Calculate the moles of Ca, P, O
Atomic mass Ca = 40.08 g/mol
Atomic mass P = 30.97 g/mol
Atomic mass O = 16.00 g/mol
Step 2: Calculate the molar ratio
Step 3: Calculate the closest whole number ratio
C: P: O = 1.50 : 1.00 : 4.00
C : P : O = 3:2:8
Therefore, the empirical formula is: C₃P₂O₈