Advertisements
Advertisements
Question
Calculate the molar mass of the following substance:
Phosphorus molecule, P4 (atomic mass of phosphorus = 31)
Advertisements
Solution
Molar mass of phosphorus molecule, P4 = 4 × atomic mass of S
= (8 × 32) u
= 124 u
APPEARS IN
RELATED QUESTIONS
Fill in the following blanks :
0.5 mole of calcium element has a mass of ............... .
How many moles of calcium carbonate (CaCO3) are present in 10 g of the substance ? (Ca = 40 u ; C = 12 u ; O = 16 u)
What weight of each element is present in 1.5 moles of sodium sulphite, Na2SO3 ?
(Atomic masses : Na = 23 u ; S = 32 u ; O = 16 u)
Calculate the number of molecules in 12.8g of sulphur dioxide gas. Take Avogadro's number as 6 x 1023.
[S = 32, 0 = 16 ]
The equation for the burning of octane is:
\[\ce{2C8H18 + 25O2 -> 16CO2 + 18H2O}\]
- How many moles of carbon dioxide are produced when one mole of octane burns?
- What volume, at STP, is occupied by the number of moles determined in (a)?
- If the relative molecular mass of carbon dioxide is 44, what is the mass of carbon dioxide produced by burning moles of octane?
- What is the empirical formula of octane?
Find the number of molecules in 1.8 g of H2O.
Calculate the number of atoms in the following:
52 g of He
1 mole of any substance contains ______ molecules.
Compute the difference in masses of 103 moles each of magnesium atoms and magnesium ions.
(Mass of an electron = 9.1×10–31 kg)
If 0.2 mol of the following substance is required how many grams of that substance should be taken?
magnesium oxide
