Answer:
The molecular formule for this unknow molecule is C2H4O2
Explanation:
The empirical formula is CH2O ( or better said CnH2nOn)
This means there are 3 elements in the formula of this molecule
⇒ Carbon (C) with a Molar mass of 12 g/mole
⇒ Hydrogen (H) with a Molar mass of 1 g/mole
⇒ Oxygen (O) with a Molar mass of 16 g/mole
We can also notice that the amount of hydrogen should 2x the amount of carbon ( also 2x the amount of oxygen).
The mass of the empirical formule = 12g/ mole + 2* 1 g/mole + 16 g/mole = 30 g/mole
To know what number is n in CnH2nOn we should divide the molecular mass by the empirical mass:
60 g/mole / 30g/mole = 2
this means n = 2
and this will give a molecular formule of C2H4O2
We can control this to calculate the molecular mass:
2*12 + 4* 1 + 2*16 = 24 + 4 + 32 = 60 g/mole
The molecular formule for this unknow molecule is C2H4O2
Moles of calcium metal used = 100/40.1=2.5
Moles of HBr need to react = 5 moles
As the molar ratio is 1 is to 2 among them
so
Moles=molarity x volume
5=2.25 x volume
volume=2.22 litres of HBr required for this reaction
ANSWER IS 2.22 LITRES
Some patterns and trend that are present in the periodic table would be
1. electronegativity (from left-to-right it increases across the table)
2. ionization (from left-to right it increases and from bottom-to-top it increases)
3. electron affinity (same as ionization energy)
4. atom radius (increases opposite way; from right-to-left it increases and from top-to-bottom it increases)
5. melting point (higher melting points with metals and lower melting point with non-metals)
6. metallic character (same as atom radius)
