Question

Conductivity of Solutions For Che 2A at RCC Introduction Electrolytes are compounds which conduct electricity when dissolved in water. Strong electrolytes consist of ionic compounds which dissociate completely when dissolved in water, AND molecular compounds which completely ionize when dissolved in water. The reactions below illustrate the dissociation reaction of strong electrolytes: Na (aq) + Cl(aq) но NaCl(s) H30 CaBra(s) HO HCl(e) Ca(aq) + 2Br (aa) H*(aq) + C'(aq) Conductivity is a measure of the ability of water to pass an electric current. Conductivity is affected by the presence of ions dissolved in water. The unit used in measuring conductivity is the siemens (s). In this experiment, students will investigate the impact of the number of ions in solution on its conductivity. Students will begin by studying the effects of different ionic compounds on the conductivity of the solution in part 1. Then in part II students will look at the effect of temperature on conductivity using a strong electrolyte and a weak electrolyte Procedure: Go to the web site https://web.mst.edu/abert/conductivity/cond.html On the left panel you will see a list of 7 cations and 5 anions. Below the list of ions you will see a drop down menu of different temperatures and a drop down menu for varying concentrations of the chosen compound. On the right panel you will see a simulated conductivity meter next to a vial of water. On the conductivity meter is a button which switches the scale at which the conductivity is read. Begin with the level in the up position to read a range of conductivity from 0-1999 us. If the conductivity goes off-scale, click next to the numbers 2-199.9 ms to move the button down and get a conductivity reading. To turn on the conductivity meter to obtain a reading, click on the dark blue button on the right side of the meter. Part 1 - Comparing Compounds For this part of the experiment, keep all compound concentrations at the web site's default value of 0.0010 mol/L, and keep all temperatures set to t = 20 deg C. Test the conductivity of every possible combination of cation and anion (a total of 35 different compounds). To do this: select one cation, one cation, click on the "conc" button and then click OK to accept the default concentration value. Finally, click on the dark blue button on the conductivity meter. The conductivity reading will appear in the gray window of the meter. For each compound, list the

Answer 1

Naming of compounds

Oxidation number of Na =+1, 20=2x2=-4

NO₂= -1 N +(-4)=-1 N =+3

Sodium nitrate (III)

Na⁺NO^-₃

Na= -1 NO₃ = -1

N + (3XO) = -1

N + (3X-2) = -1

N = +5

Sodium nitrate (V )