The coins in 1991 had more copper in them compared to the coins today. So, that is why it worth 3.3p.
Answer: hey nice to see you again, the answer is B. Microscopes allowed scientists to see the cells.
Explanation:
Na2C2O4(aq) + CaCl2(aq) -----> 2NaCl(aq) + CaC2O4(s)
Here, CaC2O4(s) is a precipitate in the reaction as a result of precipitation reaction or double displacement reaction.
As we know that double displacement reaction two metal ions displaces each other from their salt solutions.
As we know that precipitation reaction is a reaction in which precipitate is formed.
<span>Because
the question is asking moles of NH3, the compound, any subscripts are
irrelevant. It only wants to know how many moles of NH3 molecules, not
individual atoms.
Therefore, we can simply convert to moles. 1.5x10^23/6.022x10^23 = .249 moles of NH3.
(If it were to ask moles of Hydrogen, for example, you would multiply
the answer by 3, because there are 3 atoms of Hydrogen per one molecule
of NH3. But this only asks for moles of the entire compound).
hope you have a great day! :)
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