25. Describe differences between qualitative and quantitative test.
Qualitative test, identify the presence or absence of particular substances in a sample. Quantitative test determines the amount of a specific substance present in a sample.
26. What is a confirming test?
A confirming test is a positive test which confirms that the ion in question is present.
27. In the water-testing investigation, what was the purpose of
A. The reference solution?
The point of a reference is so that you can refer to that sample to see if it has the ions in the sample
B. The distilled-water blank?
The point of distilled water is to give an example of a non-reactant test.
28. Using the procedure outlined in the water-testing investigation, a student tests a sample of groundwater for iron and observes no color change. Should the student concluded that no iron is present? Explain your answer.
No the student shouldn't concluded that there is no iron present because there are three types of iron, and maybe he only tested for one type, but not the other.
29. Given and unknown mixture
a.What steps would you follow to classify it as a solution, a suspension, or a colloid?
First I would let the mixture sit for a little bit and see if any of the particles would sink down to the ground. And if they did sink down to the bottom of the class then i would know the liquid is a suspension. If the water didn't then I would do the tyndal test, to see if the laser would shine all the way though the glass. If you only see the laser only on the two ends of the glass then the water is pure and is a solution, but if you see the water in the middle then the mixture is a colloid.
B.Describe how each step would help you to distinguish among the three types of mixtures
Explained in A
30. Explain the possible risks in failing to follow the direction "shake before using" on the label of a medicine bottle.
If you have to shake the bottle before using, that means that the mixture inside a suspension, and all the particles are at the bottom of the bottle. The particles at the bottom need to be mixed with the actually solvent to make the medicine work. If you don't shake it then the liquid and the particles wont mix, and the medicine may not work
31. Why is it useful for element symbols to have international acceptance?
So you can use the symbols of the elements all around the world
32. Draw a model of a solution in which water is the solvent and oxygen gas is the solute.
Look at drawing
33. Is it possible for water to be 100% "chemical free?" Explain.
No because your water will always contain oxygen, nitrogen, and carbon dioxide.
34. Compare the physical properties of water (H2O) with the physical properties of the elements from which it is composed of.
Hydrogen is a gas, and so is oxygen. But when they are mixed together they make a liquid.
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