Answer:
The sum of the molar masses of each isotope of the element.
Atomic mass (K)= 39.1 amu
therefore:
1 mol (k)---------------------39.1 g
x------------------------------- 2.25 g
x=(1 mol * 2.25 g) / 39.1 g=0.05754....≈0.06 moles
Answer: 0.06 moles.
<h3>
Answer:</h3>
5.71 × 10² nm
<h3>
Explanation:</h3>
The product of wavelength and frequency of a wave gives the speed of the wave.
Therefore;
Velocity of wave = Wavelength × Frequency
c = f ×λ
In our case;
Frequency = 5.25 × 10^14 Hz
Speed of light = 2.998 × 10^8m/s
But;
λ = c ÷ f
= 2.998 × 10^8m/s ÷ 5.25 × 10^14 Hz
= 5.71 × 10^-7 m
But; 1 M = 10^9 nm
Therefore;
wavelength = 5.71 × 10^-7 × 10^9
= 5.71 × 10² nm
The wavelength of light wave 5.71 × 10² nm
Answer:
Explanation:
Given:
A solution contains one or more of the following ions such as Ag, and
Here the Lithium bromide is added to the solution and no precipitate forms
Solution:
Since with LiBr no precipitation takes place therefore Ag+ is absent
Here on adding to it precipitation takes place.
Precipitate is as follows,
Thus,
is present
When is added again precipitation takes place.
Therefore the reaction is as follows,
Therefore,
are present in the solution
Answer: On heating, Magnesium forms its oxide; while potassium manganate(VII) decomposes
Explanation:
Magnesium Mg, on heating forms Magnesium oxide
2Mg(s) + O2(g) --> 2MgO
Potassium permanganate KMnO4, on heating decomposes to potassium manganate K2MnO4, manganese dioxide MnO2, and Oxygen gas O2.
2KMnO4 --> K2MnO4 + MnO2 + O2
The difference in observation is that, on heating, Magnesium forms its OXIDE as product; while potassium manganate(VII) decomposes, giving OFF most of its constituents and reducing its weight.