Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with very small percentages of other elements. Our atmosphere also contains water vapor. In addition, Earth's atmosphere contains traces of dust particles, pollen, plant grains and other solid particles.
Answer:
Formula of EPSOM salt = MgSO4.7H2O
molecular mass of MgSO4.7H2O = atomic mass of Mg + atomic mass of S + 4 × atomic mass of O + 7 { 2 × atomic mass of H + atomic mass of O }
= 24 + 32 + 4× 16 + 7{ 2 × 1 + 16 } g/mol
= (24 + 32 + 64+ 126 ) g/mol
= 246 g/mol
molecular mass of total water = 7 × ( 2× atomic mass of H + atomic mass of O )
= 7 × 18 = 126 g/mol
now ,
% mass of H2O in EPSOM salt = {total molar mass of H2O/molar mass of Epsom salts }× 100
= {126/246 } × 100
= 12600/246
= 51.21 %
Explanation:
i have done it hope it helps
Answer:
(D) (CH3CH2)2NH
Explanation:
In order to decide which base is strongest we need to calculate its PKb
PKb = -log [Kb]
A large Kb value and small PKb value gives the strongest base
Compound Kb PKb
(A) C6H5NH2 - 4 x 10^-10 9.349
(B) NH3 1.76x 10^-5 4.754
(C) CH3NH2 4.4x 10^-4 3.357
(D) (CH3CH2)2NH 8.6x 10^-4 3.066
(E) C5H5N 1.7x10^-9 8.77
Clearly (CH3CH2)2NH is the strongest base.
Answer:
1: At temperatures below 542.55 K
2: At temperatures above 660 K
Explanation:
Hello there!
In this case, according to the thermodynamic definition of the Gibbs free energy, it is possible to write the following expression:
Whereas ΔG=0 for the spontaneous transition. In such a way, we proceed as follows:
1:
It means that at temperatures lower than 542.55 K the reaction will be spontaneous.
2:
It means that at temperatures higher than 660 K the reaction will be spontaneous.
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