The disodium salt of ethylene diamine tetraacetic acid can be used to estimate the following ion$(s)$ in an aqueous solution:

Which of the following cannot give iodometric titrations?

$100 \ mL$ of aqueous solution of $0.05 \ M$ $Cu^{2+}$ is added to $1 \ L$ of $0.1 \ M$ $KI$ solution. The resultant solution was titrated with $0.01 \ M$ $Na_2S_2O_3$ solution using starch indicator till blue color disappeared. What is the volume (in $mL$) of $Na_2S_2O_3$ used?

The ammonia evolved from $2 \ g$ of a compound in Kjeldahl's estimation of nitrogen neutralises $10 \ mL$ of $2 \ M \ H_2SO_4$ solution. The weight percentage of nitrogen in the compound is

The primary standard solution for the estimation of $Na_2S_2O_3$ is:

When nitrogen gas is passed through $100 \ mL$ of $0.1 \ M$ $H_2SO_4$ containing $0.30 \ g$ of an organic compound,the ammonia evolved is neutralized. To neutralize the excess acid,$20 \ mL$ of $0.5 \ M$ $NaOH$ is required. Identify the organic compound.