Physical changes happen when you do/mix something that can be reversed. Best example is ripping a paper, you can just tape it back together so it is just an observable thing that changes, which is a physical change. Chemical changes happen when you mix things and they make a new substance and can’t be reversed. The best example of this is the Statue of Liberty, which changed in color due to the chemical change between the oxygen and copper, which created a new substance (rust) which made it green instead of copper.
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Answer: 0.4533mol/L
Explanation:
Molar Mass of CaCO3 = 40+12+(16x3) = 40+12+48 = 100g/mol
68g of CaCO3 dissolves in 1.5L of solution.
Xg of CaCO3 will dissolve in 1L i.e
Xg of CaCO3 = 68/1.5 = 45.33g/L
Molarity = Mass conc.(g/L) / molar Mass
Molarity = 45.33/100 = 0.4533mol/L
The answer is Liquid iron.
Answer:

Explanation:
Hello!
In this case, given this is an acid-base neutralization and we are considering a diprotic acid, we can write the following mole-mole relationship:

It means that the moles of acid can be computed given the volume and concentration of NaOH:

It means that the approximate molar mass of the acid is:

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