b0002 stoichiometry

JC Chemistry
Chapter 01
Which of the following contains 2 mol of the stated particles ?

A. Bromine molecules in 35.5 gram of bromine gas
B. electrons in 2 grams of hydrogen gas
C. hydrogen ions in 1 dm3  of 0.1 mol dm-3  aqueous hydrochloric acid.
D. nitrogen atoms in 22.4 dm3 of nitrogen gas at standard temperature and pressure.

Answer : B

2 grams
mol H2  SO32-
 2 = 1 mol
mol e-
 1  2 = 2 mol

jc chem c01 u01 mcq02 question

Which statement about 1 mol of a metal
is correct?

A. It will produce 1 mol of electrons when oxidised
B. It contains the same number of atoms as  grams of C12
C. It has the same mass as 1 mol of C12 atoms.

D. It has the same number of atoms as 1 mol of Helium gas.

Answer : D
1 mol of metal may produce more than 1 mol of electrons, depending on the type of metal.
1/12 grams of C12 contains only 1/144 mol C atoms
The mass of 1 mol of metals vary depending on its relative molecular mass.