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Things to know!!!

Terms in this set (82)

List three descriptors that would be appropriate for describing a solid
- clumpy
-crystalline
-homogeneous
List three descriptors that would be appropriate for describing a gas.
-transparent
-colorless
-homogeneous
Describe a glass of milk as completely as you can
A clear glass of milk is an opaque white liquid
solution vs colloid
A solution is a mixture that is homogeneous. The solute is made up of tiny particles that can enter through filters and semipermeable membranes

A colloid is a mixture that have larger particles. They can pass through filters but not semipermeable membranes
Sample ID 1 (group observations)
-blue
-homogeneous
-crystalline
-solid
Sample ID 2 (group observations)
-white
-crystalline
-solid
-strong odor
Sample ID 3 (group observations)
-transparent
-colorless
-homogeneous
-gas
Sample ID 4 (group observations)
-Clear
-colorless
-viscous
-homogeneous
-liquid
Sample ID 5 (group observations)
-heterogeneous mixture
-clear liquid containing grainy solids sitting on bottom
Sample ID 6 (group observations)
-transparent
-colorless
-homogeneous
-liquid
Sample ID 7 (group observations)
-translucent
-yellow
-slightly viscous liquid
NaOH
clear colorless liquid
Phenolphthalein
-clear liquid
-colorless
NaOH + Phenolphthalein
-bright pink clear liquid

-reaction because of color change
NaCl
clear colorless liquid
Silver Nitrate
clear colorless liquid
NaCl + Silver Nitrate
cloudy, opaque white liquid

-reaction because solid formed
NaOH
clear colorless liquid
HCl
clear colorless liquid
NaOH + HCl
clear liquid was hot and steamy

reaction occurred because of heat formation
NaCl
clear colorless liquid
Distilled water
clear colorless liquid
NaCl + distilled water
clear, colorless, liquid

-no reaction
Vinegar
-clear colorless liquid
-strong odor
baking soda
-fine
-white
-powdery solid
Vinegar + Baking soda
fizzing and bubbling

reaction occurred because of fizzing and temp. change
Ammonium hydroxide
clear colorless liquid with odor
Hydrochloric acid
clear liquid
ammonium hydroxide + hydrochloric acid
clear colorless liquid

reaction occurred due to foul smell
Cu (NO3)2 copper nitrate
blue clear liquid
NH4OH (ammonium hydroxide)
clear colorless liquid
Cu (NO3)2 + NH4OH
light blue liquid

- yes because of the lighter color
copper nitrate (Cu(No3)2)
blue clear liquid
NaOH
clear colorless liquid
copper nitrate + NaOH
clumpy blue viscous jelly-like substance

reaction because of change of state (turned into jelly like)
What can you say about the liklihood of a single observation of a substance leading to a correct conclusion about its identity?
A single observation leads you closer to identifying a correct solution. The more observations the higher chance you will have a correct conclusion
How can you increase the chances of making a correct conclusion when making observations?
The more observations made, the higher chance you can make a conclusion of the substance
Can you conclude that any of the samples in part 2 you observed is pure water?
No, because all of the clear liquids that were formed had a different smell and consistency then water
How did you determine whether or not a chemical reaction had occurred in part 3? If you did not see any change, is it appropriate to conclude that a reaction did not occur? why or why not?
in part 3, a chemical reaction had occurred because the temperature of the liquid was not
A patient has a temperature of 98.6 F. Can you conclude the patient is healthy? Why or why not?
No, because the temperature of a patient does not determine their health. They could still have health issues
You are working in the kitchen. without tasting, how could you determine whether a substance was flour or sugar?
You can determine the difference between flour and sugar because sugar is a crystalline white grainy substance. Whereas, flour is a fine grainy powder
What is the difference between an observation and a conclusion? Give an example of each
An observation describes the substance, whereas a conclusion is determining what the substance is .
why do you think it is important for a nurse to make clear and complete observations that can be understood by someone else?
Observations are crucial to figure out the conclusion of what the patient could be suffering with.
average mass
total mass of _______ / number of _______
density
mass/volume
% error density
100 * (your density-expected density)/(expected density)
M=
d * V
Which of the three devices was most accurate>
The pipet was the most accurate device because the pipet showed the lowest percent error. If you ignore the negative system
Which of the following of the 3 devices was least accurate? How do you know?
The least accurate device was the beaker because it had the highest percent error. If you ignore the negative sign.
how do you determine precision?
examine range (smallest and greatest difference)
Which of the 3 devices was most precise
The most precise is the pipet device because the pipets range is the smallest. Therefore the pipet has the greatest precision
Which of the 3 devices was least precise
My least precise device is the beaker because the beaker has the largest range
Experiment 3
...
NaCl
-white
-crystalline
-solid
-slight odor
NaCl mixing with water
-clear
-liquid
-colorless
-odorless
NaCl heating in test tube
-white crystalline solid
-solid
-hot
-slight odor
NH4Cl
-white
-solid
-crystalline
NH4Cl mixing with water
-clear
-liquid
-soluble
-colorless
-odorless
NH4Cl heating in a test tube
-sublimation
-hot
-smoking
-turns to gas
-white
SiO2
-tan
-thick
-grandular
-solid
-black specks
SiO2 mixing with water
-insoluble
-tan
grandular
SiO2 heating in test tube
-tan
-thick
-grandular
-like solid
-some black specks
-hot
mixing with water is what kind of property test?
solubility in water
heating in test tube is what kind of property test?
sublimation
If you had water to a mixture of NaCl, Nh4Cl, and SiO2 what will happen to each of the three components
NaCl and NH4Cl were soluble and SiO2 was insoluble
If you heat a mixture of NaCl, NH4Cl, and SiO2, what will happen to each of the three components?
NH4Cl is sublime when heated and there was no change in NaCl and SiO2 when heated
% recovery
( total mass of the components you found/ original mass of sample) * 100
Does your experiment confirm the law of conservation of matter within a few percent?
Yes, the experiment confirms the law of conservation of matter because my percent recovery is only 1.69% off from 100%
mass percent
(amount of that individual component (g)/ original mass of the sample) * 100
In a perfect experiment, you would expect to recover 100% of the original sample. In reality, this rarely happens. If a student obtains 102% recovery, does this mean the law of conservation of matter is not true? Why might a student get such a result?
If a student obtains 102% recovery then the students experiment confirms the law of conservation. Since the student is only off of 100% by 2%. this is normal due to not getting rid of all the liquid in the test tube while heating??/
Law of conservation of mass
this is a fundamental principle of chemistry- that the amount of matter in the universe is a constant and that matter cannot be created nor destroyed.
solubility
the ability of a substance to dissolve in a liquid to produce a solution
solute
the substance present in lesser amount in a solution
solvent
the substance present in greater amount in a solution
sublimation
the process of changing directly from the solid state to the gas state without melting
property
any description of a sample of matter that is based on observation or measurements
mass percent
calculated by taking the ratio of the mass of one component over the total mass, and multiplying by 100%
Experiment 4
...
Calculate mass percent
take group number and multiply by atomic then add all individual components together and take the sum of that number and divide it by the number of the one component and multiply by 100
A student heats an unknown sample as described in the experiment but the starting sample was impure to begin the experiment. The impurity was non-volatile. Will this make the mass percent of oxygen appear to be too large, small, or unchanged?
if the impurity was non-volatile then the mass percent of oxygen will appear too small due to no oxygen
Why is it important to heat your sample several times until you obtain a constant mass for the test tube and product
due to experimental complications. repeating heating process makes sure all liquid is out of test tube
unknown component
KclO3
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