Answer:The number of atoms in 2.0 mole Al is A. 2.0 Al atoms. B. 3.0 x 1023 Al atoms.
Secondly, is aluminum an atom or molecule? Aluminum is the second element in the thirteenth column of the periodic table. It is classified as a post-transition metal and a "poor metal". Aluminum atoms contain 13 electrons and 13 protons. There are 3 valence electrons in the outer shell.
Answer:
34.9 g of Zn(OH)₂ is the maximum mass that can be formed
Explanation:
Let's state the reaction:
ZnO(s) + H₂O(l) → Zn(OH)₂ (aq)
First of all, we need to determine the moles of each reactant and state the limiting:
28.6 g . 1mol /81.38 g = 0.351 moles of ZnO
9.54 g . 1mol /18 g = 0.53 moles of water
As ratio is 1:1, for 0.53 moles of water, we need 0.53 moles of ZnO, but we only have 0.351, so the limiting reactant is the ZnO.
Ratio with the product is also 1:1. From 0.351 moles of oxide we can produce 0.351 moles of hydroxide. Let's calculate the mass:
0.351 mol . 99.4 g /1mol = 34.9 g
The Avogadro number represents the number of units in one mole of a chemical substance.
So to find the mole number of a chemical element, you divide its atom number of the Avogadro number which Na = 6.02*10^23 approx.
So n=N/Na (n=mole number, N=number of atoms, Na=Avogadro number)
n=1.0*10^15/6.02*10^23
n=1.6 * 10^-9
So 1.0*10^15 atoms of Sodium represent 1.6*10^-9 mol.
Hope this Helps! :)
Answer:
0.15 (M) of NaCl
Explanation:
An isotonic solution is defined as the solution having the same osmolarity, or the same solute concentration, as the another solution. If the two solutions are to be separated by any semipermeable membrane, then water will start flowing in equal parts from each solution and also into the other.
In the context, since it is given that the red blood cells exerts the same osmotic pressure as a 0.15 (M) of NaCl solution.
Thus, 0.15 (M) of NaCl is a isotonic solution.