Answer:
6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.
Explanation:
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given:
Concentration is decreased to 1.56 % which means that 0.0156 of
is decomposed. So,
= 0.0156
Thus,
kt = 4.1604
The expression for the half life is:-
Half life = 15.0 hours
Where, k is rate constant
So,

<u>6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.</u>
<span>Ionic compounds are normally in which physical state at room temperature in solid. The answer is A.
</span>Ionic Compounds Are Balanced. Table salt is an example of an ionic compound. Sodium<span> and </span>chlorine<span>ions come together to form </span>sodium chloride<span>, or </span>NaCl<span>. The </span>sodium atom<span> in this compound loses an electron to become Na+, while the </span>chlorine<span> atom gains an electron to become Cl-.</span>
Saliva's buffering capacity and flow of secretion are directly related to the rate and extent of demineralization. ... Saliva can act as a replenishing source and inhibit tooth demineralization during periods of low pH, while promoting tooth remineralization when the pH returns to a neutral state.
If you are provided with Cation and an Anion with different oxidation states, then there ratio in the formula unit is adjusted as such that the oxidation number of one ion is set the coefficient of other ion and vice versa,
Example:
Let suppose you are provided with A⁺² and B⁻¹, so multiply A by 1 and B by 2 as follow,
A(B)₂
In statement we are given with Co⁺³ and SO₄⁻², so multiply Co⁺³ by 2 and SO₄⁻² by 3, hence,
Co₂(SO₄)₃
Result:
Co₂(SO₄)₃ is the correct answer.