Answer:
Lavoisier made an important contribution to chemistry by the law of conservation of mass
Explanation:
The law of conservation of mass tell us, that the mass doens't change in a system. You have the same mass at the begining and in the end of a reaction.
Matter is neither created, nor destroyed in a chemical reaction.
This law also states that mass of reactants is the same of products in any chemical reaction
Answer:
Age of rock = 722 million years old
Explanation:
Using the formula; <em>fraction remaining = 0.5ⁿ</em>
where n = number of half lives elapsed.
However, from the given values, fraction remaining = 1.000 - 0.0105
fraction remaining = 0.9895
Substituting in the formula to determine the number of half-lives:
0.9895 = 0.5ⁿ
log 0.9895 = n log 0.5
-0.0045842 = -0.30103 n
number of half lives elapsed, n = 0.0152
Therefore age of rock = 0.0152 x 4.75 x 10¹⁰ years = 7.22 x10⁸ years
Age of rock = 722 million years old
Answer:
Adding a solution containing an anion that forms an insoluble salt with only one of the metal ions.
Explanation:
The student have in solution Ag⁺ and Cu²⁺ ions but he just want to analyze the silver, that means he need to separate ions.
Centrifuging the solution to isolate the heavier ions <em>FALSE </em>Centrifugation allows the separation of a suspension but Ag⁺ and Cu²⁺ are both soluble in water.
Adding enough base solution to bring the pH up to 7.0 <em>FALSE </em>At pH = 7,0 these ions are soluble in water and its separation will not be possible.
Adding a solution containing an anion that forms an insoluble salt with only one of the metal ions <em>TRUE </em>For example, the addition of Cl⁻ will precipitate the Ag⁺ as AgCl(s) allowing its separation.
Evaporating the solution to recover the dissolved nitrates. <em>FALSE</em> . Thus, you will obtain the nitrates of these ions but will be mixed doing impossible its separation.
I hope it helps!