The number of ml of hcl required to react with Zn is calculated as follows
step one: calculate the number of Zn moles
that is mass/ molar mass of Zn
7.65 g/65.38 g /mol= 0.117 moles
step two : write the reacting equation
Zn + 2 HCl ---> ZnCl2 + H2
from the equation above the reacting ratio between ZN to HCl is 1:2
therefore the moles of HCL = 2 x 0.117moles = 0.234 moles
volume of Hcl= moles of HCl / molarity of Hcl
that is 0.234 /6=0.039 L , multiply by 1000 to convert to Ml since molarity is the concentration in litres
0.039 x1000= 39ML