C.
Anthracite has the highest carbon compact and fewest impurities.
Also, the highest calorific of all types of coal except for graphite.
I believe it is either A. or C. my guess is A.
the answer is A......
it is supported by practical evidence and examples. this is the answer because he tried and tested many different ways to see what would happen so he is happy with the conclusion that what he tested is what he gets.
The question is incomplete. Complete question is:
<span>Consider the given acid ionization constants. identify the strongest conjugate base.
</span>HNO2(aq) 4.6×10−4
HCHO2(aq) 1.8×10−4
HClO(aq) 2.9×10−8
HCN(aq) 4.9×10−10
.........................................................................................................................
Correct Answer: option
4: HCN(aq) 4.9×10−10
Reason:
According to Lowry and Bronsted theory of acid and base. Stronger the acid, weaker will be the conjugate base.
In present case, ionization constant is highest of HCN i.e. 4.9×

. This signifies that, it is the strongest acid. Hence, conjugate base associated with this acid (i.e.

) is the weakest.
The fourth (last) one in 2-8-8-2.