Little bit more specific, a positive ion is called a cation and a negative ion is called an anion. But as soon as we become non-neutral, we have either moreĮlectrons or more protons, and this is true of an atom or a molecule, we will then call it an ion. Say atom when we have the same number of electrons and protons, that's when we are neutral. If you have a polyatomic ion, use the Common Ion Table to find and write the formula and. let's see if I subtract 70 I'll get 125, minus eight I have 117 neutrons. Video: How to Name Ionic Compounds with Transition Metals. Sides and what do you get? The number of neutrons is equal to 1. But what about its neutrons? Well protons plus neutrons is going to be equal to our mass number. Neutrons does it contain and what is its charge? We figured out its charge. Has a mass number of 195 and contains 74 electrons. But we're not done answering the question. This is just to get ourselves used to some of the terminology. Up there when we talkedĪbout boron being negative, a negative ion, that is an anion. Talking about a positive ion, we're talking about a cation. This is a platinum ion,Ī positive platinum ion. Four more of the positive thing than you have of the negative things. So you're going to haveĪ positive four charge. That we have four more protons than electrons. So by definition platinum hasħ8 protons, so we know that. Neutrons does it contain and what is its charge? Alright, so let's thinkĪbout this a little bit. And 195 looks prettyĬlose to that atomic mass we have there. An atom of platinum hasĪ mass number of 195. As soon as you have an imbalance between protons andĮlectrons you no longer would call it an atom, you wouldĬall it an actual ion. So you can write it like this, one minus. But this one has one extra electron, so it has one extra negative charge. The other way around? What if you were to have five protons, five protons and six electrons? What would this be? Well remember, protons define what element you're dealing with, so now if you look at whatĮlement has five protons we're dealing with boron. This you would now call an ion because it has that net charge. So this will be carbon, youĬan write it with a one plus charge like that or you couldĮven write it like this. So we're still dealing with carbon, but now we have one more positive charge than we have a negative charge. What define what element we're dealing with. So for example, if you had six protons and five electrons what would that be? Well, we still have six protons. Is if you don't have an equal amount of protons and electrons. Now you could have a carbon ion, although they aren't that typical. You have the six positive charges and the six negative charges. It is going to have six electrons and that's what makes it neutral. And if it is neutral carbon it is going to have the That one atom of carbon? Well, by definition an atom For example, if I haveĬarbon, carbon is an element. So before we talk about ions we're just going to talkĪbout the idea of an element. Talk about in this video is the notion of an ion. This Flinn handout also gives important disposal instructions.- So my apologies. In their experiment, the effect of temperature on the equilibrium shift is explored. [Flinn has a PDF handout and video with a similar lab except acetone is not used. The following year, they concluded that it was worth the wait. After a discussion about the lab, the student decided to take grade 12 chemistry, just to experience it for themselves. In fact, once a grade 11 chemistry student asked about the experiment after eyeing the set of these test tubes in the fume hood where I was evaporating off the acetone. I really enjoy experiencing students' surprised reactions when the two colourful layers form. This lab comes from Chemistry: A Modern Course, Teacher Resource Book, Merrill (1987) - still enlightening students 30 years later. The difference in density is what allows the colour change to occur at the top of the test tube. The acetone undergoes hydrogen bonding with the H 2O, causing the equilibrium to shift to the right producing more of the blue CoCl 4 2- ion. The blue layer on top of a pink layer in the cover photo is accomplished by SLOWLY adding 10 mL of acetone toĥ mL of aqueous 0.2 M CoCl 2. Students experiment with shifting the equilibrium and observing the colour change by This classic Le Châtelier’s Principle lab explores the reversible chemical reaction:Ĭo(H 2O) 6 2+ + 4Cl – + heat -> CoCl 4 2– + 6H 2O The blue colour is the result of cobalt chloride complex ions (CoCl 4 2–) in less dense acetone. On the front cover, the pink colour in the test tube comes from cobalt(II) ions in water, Co(H 2O) 6 2+.
0 Comments
Leave a Reply. |