It means <span>a substance formed by chemical union of 2 or more elements or ingredients in definite proportion by weight.</span>
Answer: 
Explanation:

cM 0 0
So dissociation constant will be:

Given: c = 0.15 M
pH = 1.86
= ?
Putting in the values we get:
Also ![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
![1.86=-log[H^+]](https://tex.z-dn.net/?f=1.86%3D-log%5BH%5E%2B%5D)
![[H^+]=0.01](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D0.01)
![[H^+]=c\times \alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Ctimes%20%5Calpha)


As ![[H^+]=[ClCH_2COO^-]=0.01](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D%5BClCH_2COO%5E-%5D%3D0.01)

![K_a=1.67\times 10^{-3]](https://tex.z-dn.net/?f=K_a%3D1.67%5Ctimes%2010%5E%7B-3%5D)
Thus the vale of
for the acid is 
Making toast is a physical change.
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There are some standard numbers that help us describe the structure of an atom and help us categorize them. Those are the atomic number, the mass number and the numbers of electrons in an atom (or ion). Atoms are electrically neutral, hence they have the same number of protons as electrons. If an atom has a charge and has thus become an ion, it is because electrons joined it or left. For example in this case, since the ion has +2 charge, 2 electrons left it and thus the ion has 4 electrons (2 electrons less than its protons). The mass number is the sum of the protons and neutrons of an atom (that are in the nucleus). In this case, this yields a mass number of 13 for this ion. The atomic number of an atom (or ion) is the total number of protons in the nucleus. Protons do not leave the nucleus except for radioactive reactions and thus the atomic number of an atom (or ion) does not change in chemical reactions. In this case, the ion has an atomic number of 6.
Do this
3.35mol HCl | 34.46g HCl
------------------------------------
1 | 1mol HCl
Multiply all the numbers on top by all the numbers on bottom.