Hello!
To do this, use the molar mass. This is how much a mole of an atom weighs. A mole is 6.02214076×10²³ atoms.
Molar masses of:
Se: 78.96 g/mol
Cu: 63.546 g/mol
Ba: 137.327 g/mol
Now, the element with the highest molar mass will have the fewest atoms. This is because the element weighs more, so therefore for the same amount of mass, there will be less of the element needed to reach that mass.
Therefore, 10g of Ba would have the fewest number of atoms.
Hope this helps!
Answer:
It take 3.5 *10² min
Explanation:
Step 1: Data given
Mass of the nickel = 29.6 grams
4.7A
Step 2: The balanced equation
Ni2+ (aq- +2e- → Ni(s)
Step 3: Calculate time
W = (ItA)/(n*F)
⇒ W = weight of plated metal in grams = 29.6
⇒ I = current in coulombs per second.
= 4.7
⇒ t = time in seconds.
⇒ A = atomic weight of the metal in grams per mole. = 58.69
⇒ n = valence of dissolved metal in solution in equivalents per mole. = 2
⇒ F = Faraday's constant in coulombs per equivalent. F = 96,485.309 coulombs/equivalent.
29.6 = (4.7 * t * 58.69)/(2*96485309)
t = 20707 seconds
t =345 minutes = 3.5 * 10² min
It take 3.5 *10² min
Le Chatelier's principle simply explains how equilibria change as you change the conditions of a reaction. If you have a reaction that is at equilibrium lets say (A + 2B <--> C + D) by removing C or D we can drive the reaction forward and products more products. I can provide a more in-depth description if needed.