Answer:

Explanation:
Here, we want to calculate the number of formula units in the given molecule
We start by getting the number of moles
To get the number of moles, we have to divide the mass given by the molar mass
The molar mass is the mass per mole
The molar mass of calcium bromide is 200 g/mol
Thus, we have the number of moles as follows:

The number of formula units in a mole is:

The number of formula units in 0.2075 mole will be:
This separation technique is a 4-step procedure. First, add H₂SO₄ to the solution. Because of common ion effect, BaSO₄ will not react, only Mg(OH)₂.
Mg(OH)₂ + H₂SO₄ → MgSO₄ + 2 H₂O
The aqueous solution will now contain MgSO₄ and BaSO₄. Unlike BaSO₄, MgSO₄ is soluble in water. So, you filter out the solution. You can set aside the BaSO₄ on the filter paper. To retrieve Mg(OH)₂, add NaOH.
MgSO₄ + 2 NaOH = Mg(OH)₂ + Na₂SO₄
Na₂SO₄ is soluble in water, while Mg(OH)₂ is not. Filter this solution again. The Mg(OH)₂ is retrieved in solid form on the filter paper.
Answer:
A
Explanation:
Because it will not cause much harm to the environment.
I hope it's right (best of luck).
Answer:
16.5 days
Explanation:
Given that:
Half life = 26.5 days
Where, k is rate constant
So,
The rate constant, k = 0.02616 days⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given:
35.0 % is decomposed which means that 0.35 of
is decomposed. So,
= 1 - 0.35 = 0.65
t = 7.8 min
<u>t = 16.5 days.</u>