The correct option is B Copper
A copper voltameter is used to determine the electrochemical equivalent of copper A voltameter or coulometer is a scientific instrument used for measuring quantity of electricity (electric charge) through electrolytic action. The SI unit of quantity of electricity is the coulomb. The voltmeter should not be confused with a voltmeter, which measures electric potential.The electrochemical equivalent, sometimes abbreviated Eq, of a chemical element is the mass of that element (in grams) transported by 1 coulomb of electricity. The electrochemical equivalent of an element is measured with a voltmeter. Element. Electrochemical equivalent.