Which of the following solution will turn blue when placed in copper vessel?

Which of the following solutions can be safely stored in a copper vessel ?

Which of the following salt solution will turn the blue litmus red?

Which one of the following solutions will turn red litmus blue?

Which of the following solutions can be stored in copper vessel?

Which of the following metal strips when placed in colourless AgNO_(3) solution, turns the solution blue?

Which of the following metals will change blue colour of copper sulphate solution ?

The following four colourless salt solutions are placed in separate test tubes and a strip of a copper is placed in each. Which of the following solution will finally turn blue? (1)NaCl (2)AgNO3 (3)ZnSO4 (4)Cd(NO3)2

Which of the following ions can turn red litmus solution blue ?