It’s because new discoveries are made all the time sometimes what was considered right may be found out to be wrong
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Answer:
1.08 x 10²⁵molecules
Explanation:
From the mole concept we know that ;
1 mole of any substance contains 6.02 x 10²³ molecules
This number is the Avogadro's number.
So;
18 mole of CH will contain:
Number of molecules of CH = 18 x 6.02 x 10²³ = 1.08 x 10²⁵molecules
The number of molecules is therefore 1.08 x 10²⁵molecules
Answer:
19.07 g mol^-1
Explanation:
The computation of the molecular mass of the unknown gas is shown below:
As we know that

where,
Diffusion rate of unknown gas = 155 mL/s
CO_2 diffusion rate = 102 mL/s
CO_2 molar mass = 44 g mol^-1
Unknown gas molercualr mass = M_unknown
Now placing these values to the above formula

After solving this, the molecular mass of the unknown gas is
= 19.07 g mol^-1