Answer:
2.94 x 
Explanation:
First we need to find out how many moles of ammonia there are, using the formula: Mass = mr x moles.
We know the mass is 83.1g, now we need to find the mR of ammonia - NH3.
N = 14, H = 1, so 14 + (3x1) = an mr of 17.
Moles = mass/ mr = 83.1/17 = 4.8882
Now we can multiply the moles by avogadro's constant to find the number of molecules:
4.8882 x (6.02 x 
) = 2.94 x molecules of ammonia
Answer: -
92.4 s
Explanation: -
The decomposition reaction of a → b has a rate constant k = 0.00132 s⁻¹
From the rate constant we see that the reaction is of zero order.
The rate equation for a zero order reaction is
A₀ - A = kt
where A₀ = initial concentration.
T = time passed since start of reaction,
A is the amount present after t time passed.
A₀ = 0.156 M
A = A₀ - 78.1% of A₀
= 0.156 - 
x 0.156
= 0.156 - 0.122
= 0.034 M
Plugging into the formula
A₀ - A = kt
0.156 - 0.034 = 0.00132 x t
t = 
= 92.4 s
t =
Using a thin stationary phase supported by an inert backing, thin layer chromatography (TLC) is a chromatographic technique used to separate the components of a mixture.
It can be carried out on an analytical scale to track the development of a reaction or on a preparative scale to purify minute quantities of a chemical. Because of its simplicity, comparatively low cost, great sensitivity, and rapid separation, TLC is an extensively used analytical method. Similar to all chromatography, TLC works on the premise that a chemical will have varying affinities for the mobile and stationary phases, which will influence how quickly it migrates. TLC aims to produce well-defined, well-separated spots.
Learn more about thin layer chromatography here-
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We generally represent an element by its symbol. provided with the atomic number and mass number or atomic mass
Atomic number is the number of protons present in an element. It is constant for an element.
The mass number of element is the sum of number of protons and number of neutrons
The atomic mass is the total mass of all the protons and neutrons present in the element (in its nucleus).
the number of electrons is equal to number of protons in a neutral atom of element.
The mass of electrons is not included in the total atomic mass of element as it is very low.
So here
12 = it is the number of protons = atomic number of element.
The true statements are
The combined mass of protons and neutrons is 24.305
You will get at first carbon dioxide by burning C:
Burn hydrogen to obtain water:
Combine them:
Now react it with Ba:
To sum up, the reaction is
, using hydrogen as a catalyst.
