Astudent is conducting an experiment to determine how cold temperatures affect the growth of tadpoles in a tank of water. which instrument would give the most accurate measurement of water temperature? a calibrated bulb thermometer that has a readout from 15 c to 25 c a calibrated digital thermometer that has a readout from 50 c to 250 c an uncalibrated bulb thermometer that has a readout from 0 c to 100 c an uncalibrated digital thermometer that has a readout from 10 c to 100 c

The instrument that would provide the student with the most accurate measurement of water temperature is a calibrated bulb thermometer, which has a readout from 15 degrees C to 25 degrees C.  

Calibration illustrates the quality and precision of measurements recorded using a piece of equipment. The aim of calibration is to reduce any measurement uncertainty by making sure the accuracy of test equipment. Calibration monitors and quantifies the uncertainties or errors within a measurement procedure to an acceptable level.  

 For reading temperatures of cold water, the most appropiate instrument is a a calibrated bulb thermometer that has a readout from 15 C to 25 C a calibrated digital

Explanation:

Among all the options, the most accurate termometer is  a calibrated digital thermometer, however, we have to keep in mind the student´s experiment , and he needs to read cold temperatures instead of hot temperatures; finally the most useful termometer giving the current experiment is the calibrated bulb thermometer, because  its readings are reliable, considering that is already calibrated under the range of temperatures that the study is taking place.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g