Answer:
Mass = 19.53 g
Explanation:
Given data:
Number of atoms of iron = 2.10 ×10²³ atoms
Mass of iron = ?
Solution:
The number 6.022 ×10²³ is called Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
1 mole contain 6.022 ×10²³ atoms
2.10 × 10²³ atoms × 1 mol / 6.022 ×10²³ atoms
0.35 mol
Mass of iron atoms:
Mass = Number of moles × molar mass
Mass = 0.35 mol × 55.8 g/mol
Mass = 19.53 g
According to boiling point elevation equation:
Δ T = i Kb m
when ΔT (change in boiling point) = 7.10 C°
and i (van't Hoff factor)= 1
and Kb = 0.520
so, by substitution:
7.10 = 1*0.520 *m
m = 7.1 / 0.52 = 13.65 m
The equation for energy of a photon is E=hv where v equals frequency and h equals the Planck constant (6.626X10^-34). So since you've been given frequency you can just plug in frequency to find the total energy in joules.
E=(3.55X10^17)(6.626X10^-34)
E=2.35223X10^-16
Not sure how many significant figures you needed. Hope this helped.
Answer: Complete ionic equations dissociate all aqueous solutions into ions. Net ionic equations show the change that occurs in chemical reactions and do not show spectator ions that are the same in reactants and products. (b) If no spectator ions were present then complete and net ionic equations would be identical.
Explanation:
Explanation:
This process ensures that the pressure inside of the graduated cylinder is the same as the atmospheric pressure in the room.
Suppose the level of water inside and outside the cylinder is same, pressure stays the same. Therefore, total pressure of the is made equal to atmospheric pressure by adjusting the height of cylinder. it is done till the water level is equal.