Important question: any possible source of error? Thanks so much!?
I did a lab of titration. I used hydrochloric acid to titrate an antacid, that has an active ingredient of calcium carbonate. I have to come up with 3 possible sources of errors (and how they affect your final lab results) and I have come up with two possibilities: • measurement and its precision • contamination between water and acid in the buret (or burrette) I've been struggling to come up with a third one..please help me and thanks so much!!!
What are some possible sources of error in a transformation lab???
I have done tons of yeast and e. coli transformations. Let me say, I have had my fair share of mistakes! Sometimes they work and sometimes they don't. That is one thing to consider... There are two ways to transform e. coli. One is by adding the DNA, letting sit on ice, then heat shocking for 40 seconds or so before letting them recover for an hour. This one doesn't seem to work as well for me. Errors can include having too long/short of a heat shock period or a strain of e. coli that just isn't as competent. Also, it is important to try nano dropping (checking the absorption of your DNA to try to quantify the amount in your tube) in order to make sure you aren't transforming too much or little DNA. Too much DNA is toxic and will kill the cells. And of course too little won't give you much either. The other way is through electroporation. This way is more of a pain in the beginning because you have to go through this long drawn out process where you make the electrocompetent bugs. Its really a pain. But once that is done, you zap it in an electroporator which is supposed to weaken the cell walls enough to allow transformation to occur. I have better luck with this although everyone is different. The errors here are, again, the amount of DNA and the temperature. It MUST BE on ice at all times. Also, you have to really be careful about the salt concentrations because if you zap with too high salt, it will pop and kill the cells (and maybe your cuvette too). And then there is always the fear of e. coli contamination... Science is hard huh.
State two possible sources of error, when doing a lab on finding the specific heat capacity of canola oil ?
1. heat lost through the (hopefully insulated) heating chamber 2. heat lost through the thermometer 3. heat lost through an inefficiency in transfer from the heating element to the oil. 4. non-calibrated thermometer, or general inaccuracies in the temperature measurement (even if the thermometer is calibrated). 5. non-uniform heating of the oil -- measuring the temperature in a 'hot' or 'cold' spot. 5a. if stirring the oil to prevent non-uniform heating, the addition of energy to the oil, from the stirring device 6. operator error (i.e. a dyslexic entry in the log book, reading the temperature measurement wrong, etc.) .
What are the sources of errors in a simple pendulum experiment and precautions to minimize them?
The sources of errors in a simple pendulum experiment are the following:human errors comes in when measuring the period using a stopwatch. The reaction time of the observer plays a significant error when starting the stopwatch and when stopping it. This error can be minimized by repeating the experiment many times. Maybe taking the average of 10 trials is enough.instrument errors - using a digital stopwatch also introduce errors. Replacing the digital stopwatch by an analog one will introduce more errors.The arc angle also introduce errors. As much as possible small angles must be used. The angle of the arc must not exceed 30 angular degrees.the friction between the swinging bob and the surrounding air is another source of error. This can be minimized by using a heavier bob than a lighter bob. The shape of the bob must be spherical to minimize this friction.The friction of the string and its pivotal anchor point cannot be eliminated.The precise measurement of the length of the pendulum is difficult to take by using meter sticks or rulers.The value of the acceleration due to gravity g in the locality is not constant and must be obtained from reliable sources.
Why is it important always to use the same balance during the course of an experiment?
to minimise any errors in your experiment. All equipment has some margin of error. By using the same balance you are keeping your margin or error to a minimum.
How is it possible for the same blood test report to show 2 different values when tested by 2 different labs? The difference is huge.
You have to specify which tests… The methods by which they do a test matters; in which case they should ideally mention the method.Sometimes..it’s the reagent they use..in that case the results are generally standardized to similar values..again..if they do not standardize they have to mention this.Drawing out sample is also a very important step. Sample handling from collection to processing is very important for results .The discrepancy can be there.Last but not the least..laboratory errors are always and mostly responsible..if the clinical correlation is not strong, most clinicians repeat tests.There is an adage…TREAT THE PATIENT,NOT THE REPORTS!…so clinical correlation is always important.