1. What is the percent by weight of C in CO2?
Molecular weight of C and Oxygen are 12 and 16 respectively?
a) 25
b) 50
c) 75
d) None of the mentioned
Explanation: Percentage by weight = mass of the component / Total mass.
2. How many moles of Hydrogen are there in 1 mole of (NH4)2HPO4?
a) 1
b) 4
c) 5
d) 9
Explanation: There are nine Hydrogen atoms in a single molecule.
3. Relative molecular masses can be calculated
a) By the relative atomic mass
b) By the relative mass of a covalent compound
c) if individual relative atomic masses are added
d) By adding relative compound masses
Explanation: Relative molecular masses can be calculated if individual relative atomic masses are added.
4. What is the percentage by weight of Nitrogen in NH3?
a) 82.35
b) 83.40
c) 88.12
d) 94.56
Explanation: Percentage by weight = mass of the component / Total mass.
5. Relative molecular mass of CO2 is _________
a) 22
b) 44
c) 66
d) 88
Explanation: Relative molecular mass = Molecular mass of C + 2(Molecular mass of Oxygen).
6. How many gms of NaOH is there in 0.002 lb mole NaOH?
a) 32.36
b) 36.32
c) 24.28
d) 28.24
Explanation: 1 lb mole of NaOH = 40 lb of NaOH = 40*454 gms of NaOH.
7. The quantity of matter present in an object is
a) Mass
b) Molecular weight
c) Mole
d) Molar mass
Explanation: The quantity of matter present in an object is mass
8. The smallest particle of a substance that is capable of independent existence is _________
a) Atom
b) Molecule
c) Electron
d) Proton
Explanation: The smallest particle of a substance that is capable of independent existence is molecule.
9. One mole of H2O equals
a) 22.4 litre at 1 atm and 250C
b) 6.02 x 1023 atoms of hydrogen and 6.02 x 1023 atoms of oxygen
c) 18 g
d) 1 gal
Explanation: One mole of H2O = 18 gms.
10. What is the percent by weight of P in the compound in P4S3?
a) 28.3
b) 56.4
c) 25.3
d) 58.3
Explanation: Percentage by weight = mass of the component / Total mass.