241) Black ppt. A dissolves in HNO₃ giving B, which gives white ppt. C with NH₄OH. C on reaction with HCl gives solution D, which gives white turbidity on addition of water. What is D?

242) A white precipitate is obtained on hydrolysis of:

243) Which of the following combines with Fe (II) ions to form a brown complex?

244) Sodium nitroprusside, when added to an alkaline solution of sulphide ions, produces purple colour ion due to the formation of:

245) Which of the following gives black precipitate when H₂S gas is passed through its solution?