H2 is a covalent bond. Each hydrogen atom shares its single electron to the other, so each hydrogen has two valence electrons (full outer shell).
Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
According to Osmotic pressure equation:
π = i M R T
When π =0.307 atm & M = 0.01 mol & R (constant)= 0.0821 L-atom/mol-K &
T= 22+273 = 295 Kelvin
So Van't half vector i = π / (MRT)
= 0.307 / (0.01 * 0.0821 * 295)
= 1.27
When there is no dissociation, i = no. of moles of Hf in 1 L of solution = (1-X)
and when there is a complete dissociation so it is equal 2X according to this equation
HF(aq) + H2O (L) ⇆ H3O (aq) + F (aq)
(1-X) X X
∴ i = (1-X) + (2x)
1.27 = 1+X
∴X= 1.27 - 1 = 0.27
∴ the percent ionization of the acid X = 27 %
Opinions are differ from facts as that we cannot change the facts but opinions can be changed as in first example it is given anthracite is better than bituminous coal may be there is another coal which is more better than anthracite. So here opinion is changed.
<h3>What is Coal ?</h3>
It is a black or brownish black sedimentary rock. It contains Sulphur, hydrogen, oxygen, carbon etc. It is always preferred as fuel. Coal was formed millions years ago when plant decay in the soil. It is obtained from dead vegetation. It is obtained from dead plants matter decay into peat and then it is converted into the coal by the process of heat.
<h3>What is Solar System ?</h3>
Solar System is made up of all the planets that revolve around our Sun. Solar System contains eight planets. These planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Thus from the above conclusion we can say that Opinions are differ from facts as that we cannot change the facts but opinions can be changed as in first example it is given anthracite is better than bituminous coal may be there is another coal which is more better than anthracite. So here opinion is changed.
Learn more about the Coal here: brainly.com/question/16607139
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Answer:
c. Forms different hydrates which have different colors
Explanation:
