Question

t in the orams ts. Conductivity Chem 113 Reading Assignment 1. Read sections 8.2-8.3 in your lecture text. 2. Review Sample Exercise 8.4 on pages 326-327 of your lecture text. Introduction Properties of Solutions: Electrolytes and Non-Electrolytes In this experiment, you will discover some properties of strong electrolytes, weak electrolytes, and non- electrolytes by observing the behavior of these substances in aqueous solutions. You will determine these properties using a conductivity Probe. When the probe is placed in a solution that contains ions, and thus has the ability to conduct electricity, an electrical circuit is completed across the electrodes that are located on either side of the hole near the bottom of the probe body (see Figure 1). This results in a conductivity value that can be read by the computer. The unit of conductivity used in this experiment is the microsiemens, or uS The size of the conductivity value depends on the ability of the aqueous solution to conduct electricity. Strong electrolytes produce large numbers of ions, which results in high conductivity values. Weak electrolytes result in low conductivity, and non-electrolytes should result in no conductivity. In this experiment, you will observe several factors that determine whether or not a solution conducts, and if so, the relative magnitude of the conductivity. Thus, this simple experiment allows you to learn a great deal about different compounds and their resulting solutions. In each part of the experiment, you will be observinga different property of electrolytes. Keep in mind that you will be encountering three types of compounds and aqueous solutions: lonic Compounds lonic compounds are usually strong electrolytes and can be expected to 100 % dissociate in aqueous solution. A regular reaction arrow will be used to denote complete dissociation if a solid is dissolved in water to form an ionic solution. lonic compounds typically have high conductivity. NaNOg(s) Na*(aq) + NO, (aq) Molecular Compounds Molecular compounds are usually non-electrolytes. They do not dissociate to form ions. Resulting solutions do not conduct electricity and will have negligible conductivities. - CH,он (аq) CH,оH (O Molecular Acids Molecular acids can partially or wholly dissociate, depending on their acid strength. Sulfuric acid (H,SO4) is a strong acid which fully dissociates, but hydrofluoric acid (HF) is a weak acid and does not fully dissociate. The equilibrium arrow is used to denote partial dissociation for weak electrolytes. The conductivity of a weak electrolyte will be lower that that of a strong electrolyte, but still measurable.

Answer 1

0x8-025 = 15 ML Solution 1.(a) Let v' volume is required. Conserving the moles of nice. noel cinitial) = nuce (final) Vx0:05 = 30X0-025 + V = 30x = 150ML (b) nacl (initial) = nuce (final) => VX0-025 = 30 x00125 P D :125 2A sodium chloride (Nocl) is a strong electoolyte because it will completely dissociate Dinto Naxci Ans: ® Acetic acid is aweak electrolyte because it will dissociate very less, since it is a weak acid. Ans: © © Ethanol is a non-electoolyte because it doesn't dissociate to produce any ions. Ans: 6 because it has dissolved salt ious in it. Ane:- © M2804 is a stoong acid so it will produce lot of Het x Sorciort. Hence it will be a strong electoolyte H2S04 — H+ +HSO4 HSO - H+ + soe overall: Hasos - 2H+ +504? © HF is a weak acid so it will dissociate very less x will have low conductivity: © Jap water will have highest conductivity