According to the Arrhenius theory, when an acidic substance is dissolved in water it will produce a solution containing only one kind of positive ion. To which ion does the theory refer?
(1) acetate (2) hydrogen
(3) chloride (4) sodium

that tool would be a compass

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.