Answer:
Explanation:
There are 118 different known <em>elements</em>.
Each element is identified by the number of protons and it is called the atomic number. For instance, the atomic number of hydrogen is 1, every hydrogen atom has one proton; the atomic number of oxygen is 8, every oxygen atom has 8 protons; the atomic number of carbon is 6, every carbon atom has 6 protons.
There are not two different elements with the same atomic number (number of protons).
The 118 known elements are listed in the periodict table in groups (columns) and periods (rows) in increasing order of atomic number (number of protons).
So, by counting the number of protons of an atom, chemists can tell the element to which the atom belong.
The complete question;
Match each type of titration to its pH at the equivalence point.
Weak acid, strong base
Strong acid, strong base
Weak base, strong acid
pH less than 7
pH equal to 7
<span>pH greater than 7
</span>Answer:
weak acid, strong base - pH greater than 7
Strong acid, strong base - pH equal to 7
Weak base, strong acid - pH less than 7
Strong acids dissociate completely to give out H⁺ ions.
Strong bases dissociate completely to give out OH⁻ ions.
When strong acids and strong bases are mixed the dissociated H⁺ and OH⁻ ions react and neutralise each other, making the solution neutral.
Weak acids cannot completely dissociate, only a fraction of H⁺ ions are dissociated. Same applies for weak bases.
When weak acid and strong base is mixed, whilst the strong acid completely dissociates, weak base only partially dissociates. Therefore the amount of H⁺ ions is greater than OH⁻ ions, overall pH is more acidic, hence less than 7.
When strong base and weak acid are mixed, strong base completely dissociates giving OH⁻ ions and weak acid only partially dissociates, therefore amount of OH⁻ ions is greater than H⁺ ions, more basic hence pH is greater than 7.
Answer:
The concentration of helium in the water is 2.405×10^-4 M
Explanation:
Concentration = Henry's law constant × partial pressure of helium
Henry's law constant = 3.7×10^-4 M/atm
Partial pressure of helium = 0.65 atm
Concentration = 3.7×10^-4 × 0.65 = 2.405×10^-4 M
If a solution of potassium hydroxide is mixed and or chemically reacted with sulphuric acid, the type of reaction that will occur is a Neutralization reaction or a unique type of a Double Replacement Reaction.
Solution = Double Replacement.
