6.0 g of a certain compound x, known to be made of carbon, hydrogen and perhaps oxygen, and to have a molecular molar mass of 138 g/mol, is burned completely in excess oxygen, and the mass of the products carefully measured:
carbon dioxide - 13.39 g
water - 2.35 g
use this information to find the molecular formula of x.

The compound X that have a molecular molar mass of 138 g/mol is

Given here,

Compound x - 6g

malar mass of x - 138g/mol

Carbon dioxide - 13.39 g

water - 2.35g

So,

The moles of Water will be 0.13 mol

The moles of Hydrogen will be 0.26

Mass of hydrogen = 0.26 g

The moles of carbon dioxide will be 0.304

The moles of carbon will be 0.304

Mass of Carbon = 3.65 g

Mass of  Oxygen = Total mass of the compound - (mass of C + mass of H)

= 6.0 g - ( 3.65 + 0.262 ) g

= 2.09 g

Moles of oxygen = 0.131

Since Oxygen has least moles,

To find the molar ratio of constituent atom, divide moles of atom from oxygen.

convert 2.3 into whole number

Hence formula will be

To know about Chemical formula, refer to the link:

link

The molecular formula of X is given as

Explanation:

mass O = Total mass of the compound - (mass of C + mass of H)

=6.0 g - ( 3.65 + 0.262 ) g

=2.09 g

Least moles is for O that is 0.131mol and dividing all by the least we get

Since 2.3 is a fraction it has to be converted to a whole number so we multiply all the answers by 3

So the empirical formula is

Empirical formula mass

Molecular formula =n × empirical formula

Compound X  =  is the Answer

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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