Based on Faraday's 1st law of electrolysis,
total electric current passed in AlCl3 = I = Q X T
where Q = electric charge, T = time (in seconds)
Given, Q = 15 A, T = 3.5 h = 3.5 X 60 X 60 s = 12600 s
∴ I = 15 X 12600 = 189000 C
Now, based on Faraday's 2nd law of electrolysis we have,
W = ZIT
where, W= weight of electrolyte deposited/evolved at any electrode
Z= electrochemical equivalent
T= time (s)
I = electric current
in present case, Electrochemical Equivalent of Al =
= 8.993 g and I = 189000 C
∴ W = 8.993 X 189000 X 12600 = 2.141X
g
Answer : 21.12 g
explanation :
- A limiting reactant is the substance that is totally consumed when the chemical reaction is complete and the reaction cannot continue without it.
- This is a limiting reactant problem because the amount of product (CO2) formed is limited by this substance (either O2 or C3H8).
- We can predict the limiting reactant by calculating number of mole for all reactants;
n (C3H8) = mass/ molar mass = 7/[(12 × 3)+(1 ×8)] = 0.16 mol
n (O2) = mass/ molar mass = 98/(16 × 2) = 3 mol
But we know from this balanced equation that for the reaction to continue, for (n) of propane there must be (5n) of oxygen. Clearly we have more oxygen than required for the reaction to continue as
[ 3 O2 mol > (0.16 propane mol × 5) . Hence, the limiting reactant is propane.
- Using cross multiplication,
0.16 mol propane → 1 mol propane
? → 3 mol CO2
So (n) of CO2 produced = 0.16 × 3 / 1 = 0.48 mol ,
And mass of CO2 produced = n × molar mass = 0.48 × [12 + (16 ×2)] = 21.12 g..
Answer: Option D is correct.
Explanation: Equation given by de Broglie is:
where, = wavelength of the particle
h = Planck's constant
m = mass of the particle
v = velocity of the particle
In option A, football will have some mass and is moving with a velocity of 25 m/s, hence it will have some wavelength.
In Option B, unladen swallow also have some mass and is moving with a velocity of 38 km/hr, hence it will also have some wavelength.
In Option C, a person has some mass and is running with a velocity of 7 m/hr, hence it will also have some wavelength.
As, the momentum of these particles are large, therefore the wavelength will be of small magnitude and hence, is not observable.
From the above, it is clearly visible that all the options are having some wavelength, so option D is correct.
Answer:
Heating of the liquid water in a microwave.
Explanation:
Radiation is a form of heat transfer process that does not require a material medium rather it travels through space or vacuum in the form of electromagnetic waves or radiation. Heat transfer by radiation occurs in the form of microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. Some common examples of heat transfer by radiation is the warming of the Earth by the Sun, the warmth one experiences while sitting by the campfire, or the heating up of foods in a microwave.
Black bodies or surfaces are good absorbers as well as emitters of radiation. On the other shiny or white surfaces are poor radiators of heat.
From the above discussion on radiation, it can be seen that when the chemist takes the liquid and heats it in a microwave, the heat absorbed by the liquid to change to gaseous state is transferred through radiation.