320905
The number of moles of lead nitrate needed to coagulate 2 moles of colloidal \(\left[ {{\text{AgI}}} \right]\,{{\text{I}}^{\text{ - }}}\,{\text{is}}\)
1 2
2 1
3 \(1 / 2\)
4 \(2 / 3\)
Explanation:
\(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) is a negative colloid. One mole of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1/2 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\) for coagulation so,two moles of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\)
CHXII05:SURFACE CHEMISTRY
320906
On addition of \(1 \mathrm{ml}\) solution \({\rm{10\% }}\,\,\,{\rm{NaCl}}\) to \(10 \mathrm{ml}\) gold sol in the presence of \(0.25 \mathrm{~g}\) of starch, the coagulation is just prevented. Starch has the following gold number
1 0.025
2 0.25
3 0.5
4 250
Explanation:
By definition gold number of starch is the amount of starch in \(\mathrm{mg}\) added to \(10 \mathrm{~mL}\) standard gold sol which prevents the coagulation of gold on adding \(1 \mathrm{~mL}\) of \({\rm{10\% }}\,\,{\rm{NaCl}}\) solution. So the amount of starch is \(0.25 \mathrm{~g}=250 \mathrm{mg}\). Hence, gold number is 250 .
CHXII05:SURFACE CHEMISTRY
320907
Which of the following electrolytes will have maximum flocculation value for \(\mathrm{Fe}(\mathrm{OH})_{3}\) sol?
Flocculation value \(\propto \dfrac{1}{\text { Coagulating power }}\) \(\mathrm{Fe}(\mathrm{OH})_{3}\) is a positively charged sol. To coagulate \(\mathrm{Fe}(\mathrm{OH})_{3}\), negatively charged electrolyte is used and greater the value of negative charge, coagulating power will be strong. Among the given electrolytes, \({\rm{NaCl}}\) has lowest coagulating power, so its flocculation value will be maximum.
CHXII05:SURFACE CHEMISTRY
320908
Which of the following colloids cannot be easily coagulated?
1 Multimolecular colloids
2 Irreversible colloids
3 Lyophobic colloids
4 Macromolecular colloids
Explanation:
Macromolecular colloids are quite stable and resemble true solution in many respects.
320905
The number of moles of lead nitrate needed to coagulate 2 moles of colloidal \(\left[ {{\text{AgI}}} \right]\,{{\text{I}}^{\text{ - }}}\,{\text{is}}\)
1 2
2 1
3 \(1 / 2\)
4 \(2 / 3\)
Explanation:
\(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) is a negative colloid. One mole of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1/2 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\) for coagulation so,two moles of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\)
CHXII05:SURFACE CHEMISTRY
320906
On addition of \(1 \mathrm{ml}\) solution \({\rm{10\% }}\,\,\,{\rm{NaCl}}\) to \(10 \mathrm{ml}\) gold sol in the presence of \(0.25 \mathrm{~g}\) of starch, the coagulation is just prevented. Starch has the following gold number
1 0.025
2 0.25
3 0.5
4 250
Explanation:
By definition gold number of starch is the amount of starch in \(\mathrm{mg}\) added to \(10 \mathrm{~mL}\) standard gold sol which prevents the coagulation of gold on adding \(1 \mathrm{~mL}\) of \({\rm{10\% }}\,\,{\rm{NaCl}}\) solution. So the amount of starch is \(0.25 \mathrm{~g}=250 \mathrm{mg}\). Hence, gold number is 250 .
CHXII05:SURFACE CHEMISTRY
320907
Which of the following electrolytes will have maximum flocculation value for \(\mathrm{Fe}(\mathrm{OH})_{3}\) sol?
Flocculation value \(\propto \dfrac{1}{\text { Coagulating power }}\) \(\mathrm{Fe}(\mathrm{OH})_{3}\) is a positively charged sol. To coagulate \(\mathrm{Fe}(\mathrm{OH})_{3}\), negatively charged electrolyte is used and greater the value of negative charge, coagulating power will be strong. Among the given electrolytes, \({\rm{NaCl}}\) has lowest coagulating power, so its flocculation value will be maximum.
CHXII05:SURFACE CHEMISTRY
320908
Which of the following colloids cannot be easily coagulated?
1 Multimolecular colloids
2 Irreversible colloids
3 Lyophobic colloids
4 Macromolecular colloids
Explanation:
Macromolecular colloids are quite stable and resemble true solution in many respects.
320905
The number of moles of lead nitrate needed to coagulate 2 moles of colloidal \(\left[ {{\text{AgI}}} \right]\,{{\text{I}}^{\text{ - }}}\,{\text{is}}\)
1 2
2 1
3 \(1 / 2\)
4 \(2 / 3\)
Explanation:
\(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) is a negative colloid. One mole of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1/2 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\) for coagulation so,two moles of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\)
CHXII05:SURFACE CHEMISTRY
320906
On addition of \(1 \mathrm{ml}\) solution \({\rm{10\% }}\,\,\,{\rm{NaCl}}\) to \(10 \mathrm{ml}\) gold sol in the presence of \(0.25 \mathrm{~g}\) of starch, the coagulation is just prevented. Starch has the following gold number
1 0.025
2 0.25
3 0.5
4 250
Explanation:
By definition gold number of starch is the amount of starch in \(\mathrm{mg}\) added to \(10 \mathrm{~mL}\) standard gold sol which prevents the coagulation of gold on adding \(1 \mathrm{~mL}\) of \({\rm{10\% }}\,\,{\rm{NaCl}}\) solution. So the amount of starch is \(0.25 \mathrm{~g}=250 \mathrm{mg}\). Hence, gold number is 250 .
CHXII05:SURFACE CHEMISTRY
320907
Which of the following electrolytes will have maximum flocculation value for \(\mathrm{Fe}(\mathrm{OH})_{3}\) sol?
Flocculation value \(\propto \dfrac{1}{\text { Coagulating power }}\) \(\mathrm{Fe}(\mathrm{OH})_{3}\) is a positively charged sol. To coagulate \(\mathrm{Fe}(\mathrm{OH})_{3}\), negatively charged electrolyte is used and greater the value of negative charge, coagulating power will be strong. Among the given electrolytes, \({\rm{NaCl}}\) has lowest coagulating power, so its flocculation value will be maximum.
CHXII05:SURFACE CHEMISTRY
320908
Which of the following colloids cannot be easily coagulated?
1 Multimolecular colloids
2 Irreversible colloids
3 Lyophobic colloids
4 Macromolecular colloids
Explanation:
Macromolecular colloids are quite stable and resemble true solution in many respects.
320905
The number of moles of lead nitrate needed to coagulate 2 moles of colloidal \(\left[ {{\text{AgI}}} \right]\,{{\text{I}}^{\text{ - }}}\,{\text{is}}\)
1 2
2 1
3 \(1 / 2\)
4 \(2 / 3\)
Explanation:
\(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) is a negative colloid. One mole of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1/2 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\) for coagulation so,two moles of \(\left[ {{\rm{AgI}}} \right]{{\rm{I}}^{\rm{ - }}}\) requires 1 mole of \({\rm{P}}{{\rm{b}}^{{\rm{ + 2}}}}\)
CHXII05:SURFACE CHEMISTRY
320906
On addition of \(1 \mathrm{ml}\) solution \({\rm{10\% }}\,\,\,{\rm{NaCl}}\) to \(10 \mathrm{ml}\) gold sol in the presence of \(0.25 \mathrm{~g}\) of starch, the coagulation is just prevented. Starch has the following gold number
1 0.025
2 0.25
3 0.5
4 250
Explanation:
By definition gold number of starch is the amount of starch in \(\mathrm{mg}\) added to \(10 \mathrm{~mL}\) standard gold sol which prevents the coagulation of gold on adding \(1 \mathrm{~mL}\) of \({\rm{10\% }}\,\,{\rm{NaCl}}\) solution. So the amount of starch is \(0.25 \mathrm{~g}=250 \mathrm{mg}\). Hence, gold number is 250 .
CHXII05:SURFACE CHEMISTRY
320907
Which of the following electrolytes will have maximum flocculation value for \(\mathrm{Fe}(\mathrm{OH})_{3}\) sol?
Flocculation value \(\propto \dfrac{1}{\text { Coagulating power }}\) \(\mathrm{Fe}(\mathrm{OH})_{3}\) is a positively charged sol. To coagulate \(\mathrm{Fe}(\mathrm{OH})_{3}\), negatively charged electrolyte is used and greater the value of negative charge, coagulating power will be strong. Among the given electrolytes, \({\rm{NaCl}}\) has lowest coagulating power, so its flocculation value will be maximum.
CHXII05:SURFACE CHEMISTRY
320908
Which of the following colloids cannot be easily coagulated?
1 Multimolecular colloids
2 Irreversible colloids
3 Lyophobic colloids
4 Macromolecular colloids
Explanation:
Macromolecular colloids are quite stable and resemble true solution in many respects.
