"Indoor environments are much less polluted than outdoor <span>environments" is the best option since indoor environments often rely on separate air and ventilation systems. </span>
Answer:
42.29 g of BrF₃.
Explanation:
Molar mass of OF2 = 16 + (2 * 19)
= 54 g/mol
Number of moles of OF₂ = mass / molar mass
= 25/54
= 0.46 mol.
Number of OF₂ molecules = number of moles * avogadros constant
= 0.46 * 6.022 x 10²³
= 2.8 x 10^23 molecules of OF2.
Since each OF₂ molecule has 2 Fluorine atoms,
Number of Fluorine atoms in 25.0 g of OF₂ = 2 x 2.8 x 10²³
= 5.576 x 10²³ atoms of Fluorine.
Since 1 BrF₃ molecule has 3 Fluorine atoms,
number of BrF₃ molecules = Number of Fluorine atoms / 3
= 5.576 x 10²³ / 3
= 1.8587 x 10²³ molecules of BrF₃.
Number of moles of BrF₃ = number of molecules of BrF₃ / Avogadros constant
= (1.8587 x 10²³) / (6.022 x 10²³ )
= 0.30865 moles of BrF₃.
Molar mass of BrF₃ = 80 + (19 * 3)
= 137 g/mol
mass of BrF₃ = number of moles * molar mass
= 0.30865 * 137
= 42.29 g of BrF₃.
Answer:
Explanation:
Calcium bicarbonate dissolved in hard water can easily be removed by heating the hard water . On heating , it decomposes to give calcium carbonate which is insoluble and therefore can be filtered out .
Ca( HCO₃)₂ = CaCO₃ + CO₂ + H₂O.
In this way hardness of water is removed .
Answer : The time taken for the reaction is, 28 s.
Explanation :
Expression for rate law for first order kinetics is given by :
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 0.0632
t = time taken for the process = ?
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount or concentration of the reactant = 1.28 M
![[A]](https://tex.z-dn.net/?f=%5BA%5D)
= amount or concentration left time 't' = 
Now put all the given values in above equation, we get:
Therefore, the time taken for the reaction is, 28 s.
