The SAME number of molecules are in ANY “mole” of a compound or element. So, you only need to ... 24 g116 g/mol=0.207 moles of FeF3.
The answer is D. energy of activation increase
Answer:
The object is moving at a constant speed.
The kinetic energy of emitted electrons when cesium is exposed to UV rays of frequency 1.80 * 10 ^15 is 3.054 x 10 ^- 19 J.
Explanation:
To calculate the kinetic energy of emitted electrons,
It is given that the frequency is 1.80* 10^15 Hz
We have,
KE = E – Eo = hv –hvo
Where, h = 6.626 x 10^ - 34 Js
Given frequency = 1.4 x 10 ^ 15 Hz
vo (Threshold frequency) for cesium = 9.39 x 10 ^ 14 Hz
Applying in equation,
we get
KE = 6.626 x 10^34 (1.4 x 10^15 - 9.39 x 10^14)
KE= 3.054 x 10^-19 J
[Note: Here, threshold frequency of Cesium is not provided. Apply the correct threshold frequency from the part A]
Answer:
N2O4
Explanation:
To obtain the molecular formula of the compound, first, let us calculate the empirical formula for the compound. This is illustrated below:
N = 0.606g
O = 1.390g
Next, we divide the above by their molar masses
N = 0.606/14 = 0.0432
O = 1.390/16 = 0.0869
Next, we divide by the smallest
N = 0.0432/0.0432 = 1
O = 0.0869/0.0432 = 2
The empirical formula is NO2
The molecular formula is given by:
[NO2]n = 92
[14 + (16x2)]n = 92
[14 +32]n = 92
46n = 92
Divide both side by the coefficient of n i.e 46
n = 92/46
n = 2
The molecular formula = [NO2]n = [NO2]2 = N2O4