On addition of one mL of 10% NaCl solution to 10mL gold sol in presence of 0.25gm of starch, the coagulation is just prevented, starch has gold number:
A
0.25
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
0.025
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2.5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None of these
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct option is D None of these
Gold Number Of a protective colloid is a minimum weight of it in milligram which must be added to 10ml of a standard red gold sol so that no coagulation of the gold sol. Smaller the gold number of a protective colloid, the greater is the protective action. As 0.25 gram of starch is added therefore gold number will be 0.00025 as it is taken in milligrams.