Answer:
Demonstration 1 showed a chemical change because a new gaseous substance was formed, and demonstration 2 showed a physical change because liquid water became water vapor.
Explanation:
Chemical changes alter the chemical makeup of a subject, and a physical change only alters the appearance of a subject, not the chemical makeup.
Answer:
4.52 mol/kg
Explanation:
Given data:
Mass of lithium fluoride = 22.1 g
Mass of water = 188 g
Molality = ?
Solution:
Molality:
It is the number of moles of solute into kilogram of solvent.
Formula:
Molality = number of moles of solute / kilogram solvent
Mathematical expression:
m = n/kg
Now we will convert the grams of LiF into moles.
Number of moles = mass/ molar mass
Number of moles = 22.1 g/ 26 g/mol
Number of moles = 0.85 mol
Now we will convert the g of water into kg.
Mass of water = 188 g× 1kg/1000 g = 0.188 kg
Now we will put the values in formula.
m = 0.85 mol / 0.188 kg
m = 4.52 mol/kg
The hypothesis should be; "Increasing the amount of ice increases the rate at which the ice will melt"
<h3>What is a hypothesis?</h3>
The term hypothesis refers to a tentative explanation that could be applied in order to explain an observation. When we give a hypothesis, it must be subjected to rigorous experimentation thus it can be confirmed or repelled by experiment.
Now, we can see that the question here is; "How does the amount of salt added to ice affect the rate at which the ice will melt?" This implies that the correct hypothesis here ought to have to do with the impact of the amount of ice in the affirmative.
Thus, the hypothesis should be; "Increasing the amount of ice increases the rate at which the ice will melt"
Learn more about hypothesis:brainly.com/question/13025783
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Since tasting or touching the texture or surface could be deemed unsafe. It would be best to use a pH meter or litmus paper. pH meter will accurately determine pH. Litmus paper if red will be acidic and basic if blue. You can also perform conductivity test. Else, you can also perform hydrogen test.
