(9am to 6pm)

Ask Questions, Get Answers

Want help in doing your homework? We will solve it for you. Click to know more.

$10^{-4}\;g$ of gelatin is required to be added to $\;100\;cm^{3}$ of a standard gold sol to just prevent its coagulation by the addition of $\;1\;cm^{3}$ of $\;10\%\;$ Nacl solution to it . Hence , the gold number of gelatin is


1 Answer

Need homework help? Click here.
Answer : $\;0.01$
Explanation :
By definition , gold number is the number of milligrams of dry protective colloids required to just prevent the coagulation of 10 mL of red gold sol when 1 mL $\;(0r\;1\;cm^{3})\;$ of $\;10\%\;$ Nacl solution is added to it .
Here the amount of gelatin required to protect 10 mL $\;or\;10\;cm^{3}\;$ of gold sol $\;=\large\frac{10^{-4}\times10}{100}=10^{-5}\;g=10^{-2}\;mg$
Therefore , Gold number = 0.01
answered Mar 19, 2014 by yamini.v

Related questions