Answer:
Hydrogen
Explanation:
Just to provide some background, an element is a pure substance consisting of only one type of atom. An atom is the smallest constituent of matter. All elements are comprised of a single type of atom (e.g., gold is composed of gold atoms, helium of helium atoms, phosphorus phosphorus, and so on).
A molecule is a group of two or more atoms. They can be the same atom (homonuclear), such as or different atoms (heteronuclear).
Some examples of homonuclear molecules include:
Hydrogen (H2)
Nitrogen (N2)
Phosphorus (P4)
Some examples of heteronuclear molecules include:
Carbon dioxide (CO2)
Sulfuric acid (H2SO4)
Methane (CH4)
Answer:
A mixture of 100. mL of 0.1 M HC3H5O3 and 50. mL of NaOH
Explanation:
The pH of a buffer solution is calculated using following relation

Thus the pH of buffer solution will be near to the pKa of the acid used in making the buffer solution.
The pKa value of HC₃H₅O₃ acid is more closer to required pH = 4 than CH₃NH₃⁺ acid.
pKa = -log [Ka]
For HC₃H₅O₃
pKa = 3.1
For CH₃NH₃⁺
pKa = 10.64
pKb = 14-10.64 = 3.36 [Thus the pKb of this acid is also near to required pH value)
A mixture of 100. mL of 0.1 M HC3H5O3 and 50. mL of NaOH
Half of the acid will get neutralized by the given base and thus will result in equal concentration of both the weak acid and the salt making the pH just equal to the pKa value.
It has to be moist in the grass
Answer:Mass of Potassium chloride =1.762g
Explanation:
Mass of empty beaker = 23.100 g
Mass of beaker with Potassium chloride = 24.862g
Mass of Potassium chloride = Final weight - initial weight = Mass of beaker with Potassium chloride - Mass of empty beaker = 24.862-23.100 = 1.762g