A) Magnesium + Chlorine -> Magnesium chloride ( Mg + Cl2 -> MgCl2)
b) Potassium + Oxygen -> Potassium oxide
( 2K + O2 -> K2O )
c) Sodium + Bromine -> Sodium bromide
( 2Na + Br2 -> 2NaBr)
d) Carbon + Oxygen -> Carbon dioxide
( C + O2 -> CO2 ) This reaction occurs when heated.
The answer to that question is B
Composting is not a technological way of improving air quality.
I hope this helps!
Answer : The molecular formula of a compound is, 
Solution : Given,
Mass of C = 64.03 g
Mass of H = 4.48 g
Mass of Cl = 31.49 g
Molar mass of C = 12 g/mole
Molar mass of H = 1 g/mole
Molar mass of Cl = 35.5 g/mole
Step 1 : convert given masses into moles.
Moles of C = 
Moles of H = 
Moles of Cl = 
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = 
For H = 
For Cl = 
The ratio of C : H : Cl = 6 : 5 : 1
The mole ratio of the element is represented by subscripts in empirical formula.
The Empirical formula = 
The empirical formula weight = 6(12) + 5(1) + 1(35.5) = 112.5 gram/eq
Now we have to calculate the molecular formula of the compound.
Formula used :


Molecular formula = 
Therefore, the molecular of the compound is, 