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
Answer:
electron
Explanation:
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol = e⁻
Mass = 9.10938356×10⁻³¹ Kg
Mass in amu = 1/1838 = 5.4 × 10⁻⁴amu
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P⁺
Symbol of neutron= n⁰
Mass of proton=1.672623×10⁻²⁷ Kg
Mass of neutron=1.674929×10⁻²⁷Kg
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom
Cr{3+} + 3 NaF → CrF3 +
3 Na{+} <span>
First calculate the total mols of NaF.
(0.063 L) x (1.50 mol/L NaF) = 0.0945 mol NaF total </span>
Using stoichiometric
ratio:
<span>0.0945 mol NaF * (1 mol Cr3+ / 3 mol NaF) * (51.9961 g Cr3+/mol) =
1.6379 g Cr3+</span>
Specific heat means the amount heat needed when unit mass of a substrate increase one degree of temperature. So the specific heat = the heat absorbed/(the mass of the substrate * change in temperature) = 264.4/(16*35)=0.472 J/(g*℃）
