which is an observation?
A) an acid produces h+
b) an acid produces H3O+
C) an acid turns litmus paper blue
d) an acid has a proton which can be given to another substance
btw, the answer is C, but WHY? can someone please explain it to me? thanks in advance
2007-06-12 10:04:44 · 6 answers · asked by zxc 2 in Science & Mathematics ➔ Chemistry
An observation in chemistry is something which can be seen by the naked eye.
You cannot physically see a,b or d, but you can see litmus paper turning blue.
It's really as simple as that, best of luck!
2007-06-12 10:10:41 · answer #1 · answered by luckyb 2 · 0⤊ 0⤋
only C) can be observed by visual inspection. A very unlikely one by the way. Normally litmus paper turns red under acid conditions. If a substance turns litmus paper blue it indicates a basic pH. I think C) would indicate the substance is rather an alkali, not an acid.
a) and b) are processes not observable by simple inspection. There is no apparent change when they occur.
d) is a fact, not an observable process.
2007-06-12 17:19:09 · answer #2 · answered by Manuelon 4 · 0⤊ 0⤋
The Observable answer is that C). is incorrect. An acid turns litmus paper RED.
2007-06-12 17:42:25 · answer #3 · answered by Norrie 7 · 0⤊ 0⤋
The answer is C because the guys at the examination board setting your syllabus are trying to get you to discern the difference between results you can directly measure, or OBSERVE, i.e. for example see visually, and results you can't easily measure/observe.
You are rightly confused by this, as I was at GCSE, because the word 'observe' is being misused by these examiners, as it does not necessarily only mean see/smell/feel/touch/taste! If these people were not foolish, they would say something along the lines of 'DIRECT observation'.
Rest assured that if you pursue science beyond school, you won't find your teachers and colleagues this irritating!
2007-06-12 17:37:24 · answer #4 · answered by Abondance Roquefort 2 · 0⤊ 1⤋
None of those answers are satisfactory. BF3 and SbF5 are extraordinarily powerful acids and they have nothing to do with protons. Al(OCH3)3 is a Lewis acid and a Bronsted base.
Acidity is a redox phenomenon. Electron acceptors are acids, electron donors are bases. Now extend that to solvo-cation and solvo-anion acid base theory.
2007-06-12 17:11:33 · answer #5 · answered by Uncle Al 5 · 0⤊ 1⤋
The other three (A, B, and D) are facts that you have to be taught. If no one ever told you that, you would not know it.
C on the other hand is something you can test and see. You don't have to just know it. You can experiment to find it out.
2007-06-12 17:10:20 · answer #6 · answered by yankee_fan907 2 · 1⤊ 0⤋