Which method is employed for concentrating sulfide ores?

For the reaction, $2{\rm{F}}{{\rm{e}}^{3 + }} + {\rm{S}}{{\rm{n}}^{2 + }} o 2{\rm{F}}{{\rm{e}}^{2 + }} + {\rm{S}}{{\rm{n}}^{4 + }}$ The normality of ${\rm{SnC}}{{\rm{l}}_2}$ (mol.wt. = 189.7) solution prepared by dissolving 47.5 g in acid solution and diluting with ${{\rm{H}}_2}{\rm{O}}$ to a total of 2.25 litre is :

2 grams of sodium hydroxide was treated with $50 \mathrm{mL}$ of $0.75 \mathrm{M}$ HCl solution. The mass of sodium hydroxide left unreacted is equal to

0.5 grams of sodium hydroxide was treated with $12.5 \mathrm{mL}$ of $0.75 \mathrm{M}$ HCl solution. The mass of sodium hydroxide left unreacted is equal to

A 0.5 molal aqueous solution of urea ($CON_2H_4$) is prepared. What is the mole fraction of urea?

Which of the following describes a 0.5 molal solution?

Which of the following concentration terms is NOT affected by temperature?

An increase in temperature typically causes which of the following changes in a chemical reaction?

In the following change, $3{\rm{Fe}} + 4{{\rm{H}}_2}{\rm{O}} o {\rm{F}}{{\rm{e}}_3}{{\rm{O}}_4} + 4{{\rm{H}}_2}$. If the atomic weight of iron is 56, then its equivalent weight will be :

When one mole of ${\rm{KMn}}{{\rm{O}}_4}$ reacts with $HCl$, the volume of chlorine liberated at $NTP$ will be:

A binary solution of liquids A and B shows positive deviation from Raoult's law. Which of the following statements is TRUE?