Answer:
1. C. [tex]10.5 *10^{23[/tex] molecules
2. C. [tex]9.04*10^{21}[/tex] molecules
3. D. [tex]89.64*10^{-24[/tex] g
Explanation:
1. To find the molecules of manganese from moles use this equation:
[tex]moles (x)*\frac{6.022 *10^{23} molecules }{1 mole}[/tex]
Insert the amount of moles given (1.75) into the equation and solve:
[tex]1.75moles*\frac{6.022 *10^{23} molecules }{1 mole}[/tex] = [tex]1.05 *10^{24[/tex] molecules.
In the question they have the answer as [tex]10.5 *10^{23[/tex] which is the same as [tex]1.05 *10^{24[/tex]. So, [tex]10.5 *10^{23[/tex] is the answer.
2. To find molecules from grams per mole, use this equation:
[tex]x grams *\frac{1 mol}{mass(g)} *\frac{6.022*10^{23} molecules}{1 mol}[/tex]
The molar mass of AlCl3 is 133.34 g/mol, and we want to know how many molecules in 2 grams. Plug these into the equation.
[tex]2 g *\frac{1 mol}{133.34g} *\frac{6.022*10^{23} molecules}{1 mol}[/tex] = [tex]9.04*10^{21}[/tex] molecules
The answer will be C. [tex]9.04*10^{21}[/tex] molecules.
3. To find the mass of the hydrogen atoms, use this equation:
[tex]x u*\frac{1.66*10^{-24}g}{1u}[/tex]
We are given 54 u. Plug this into the equation and solve:
[tex]54 u*\frac{1.66*10^{-24}g}{1u} = 8.964*10^{-23[/tex] grams
Once again, the question gives us this answer in a different form of [tex]89.64*10^{-24[/tex] g, but they are the same. So, the final answer is D. [tex]89.64*10^{-24[/tex] g.
I hope this helps! If you have any questions about my work feel free to leave them in the comments!
