To solve this problem, we make use of the Faraday’s law
for Electrolysis. The formula is given as:
I t = m F / e
where the variables are,
I = current = 24.4 A
t = time = 46 min = 2760 s
m = mass produced = (unknown)
F = Faraday’s constant = 96500 C/equivalent
e = gram equivalent weight of gold
The gram equivalent weight is calculated by dividing the
molar mass with the amount of charge produced per atom. Gold has charge of 3+
therefore the gram equivalent weight is:
e = (196.97 g/mol)(1 mol/3 equivalents) = 65.66
g/equivalents
Solving for the mass m:
m = e I t / F
m = (65.66 g) (24.4 A) (2760 s) / (96500 C)
m = 45.82 g
There are 0.31 mol in h3po4
Answer:
Q = -811440 J
Explanation:
Given data:
Mass of oil = 2.76 Kg (2.76× 1000 = 2760 g)
Initial temperature = 191 °C
Final temperature = 23°C
Specific heat capacity of oil = 1.75 J/g.°C
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 23°C - 191 °C
ΔT = -168°C
Q = 2760 g ×1.75 J/g.°C ×-168°C
Q = -811440 J
Negative sign show heat is released.
Answer:
Option (C)
Explanation:
A metal detector is usually defined as an instrument that is commonly used to detect the presence of metals in the bags and luggage. It is very widely used in places like airports, railway stations, and other important official places.
This device is generally activated with the help of electromagnetic induction. It contains a single or numerous inducting coils which are connected to the elements placed on the ground surface. These used materials are metallic in nature. Within the region of the electromagnetic field, when any metallic substance enters, it immediately gains energy and thereby transmits an electromagnetic field of its own.
Thus, the correct answer is option (C).
