Consider the following reaction: 2Al (s) + 6HCl (aq) → 2AlCl3 (aq) + 3H2 (g).
A 0.080 mole piece of aluminum reacted completely in 20 s.
The rate of formation of hydrogen gas is:

the awnser is group 12

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally