Question

Please answer quickly

Answer 1

a) molar mass of Methane = 12+4 => 16 grams per mole.

So, 38.4 grams of Methane will be 38.4/16 => 2.4 moles.

Each mole contains 6.023 X 10^23 molecules

Also, if two gases have the same number of molecules, they contain the same number of moles as well.

Hence, mass of 2.4 moles of C2H6 =?

molar mass of ethane = 2X12 + 6 => 30 grams per mole.

So, 30 X 2.4 => 72 grams of Ethane.

b) ratio of sulphur is to oxygen in the oxide by mass= 2:3

S= 32  ,   O= 16.

let number of sulphur atoms present in one molecule of the oxide be x.

let number of oxygen atoms present  in one molecule of the oxide be y.

So, according to the given, 2/3 =(32*x)/(16*y)

2/3= 2x/y

1/3=x/y

x/y =1/3

Hence, ratio of number of sulphur atoms  to number of oxygen atoms in one molecule of the oxide is 1:3.

So, the formula of the compound will be S₁ O₃

So, the oxide has the formula SO3 and its name is Sulphur trioxide.

c) We have to compare the masses of 10²² molecules of oxygen and 10²² molecules of ozone.

molar mass of Oxygen= 2 X 16 => 32 grams per mole.

molar mass of Ozone= 3 X 16 => 48 grams per mole.

1 mole of any gas will have 6.023 X 10^23 molecules of that gas in it.

For Oxygen gas: 6.023 X 10^23 molecules have a mass of 32 grams.

So, mass of 10^22 molecules of oxygen will be=?

=> (32 X 10^22)/(6.023 X 10^23) =>32/6.023 X10^-1 => 32/60.23 grams.

For Ozone gas: 6.023 X 10^23 molecules have a mass of 48 grams.

So, mass of 10^22 molecules of Ozone will be=?

=> (48 X 10^22)/(6.023 X 10^23) => 48/60.23 grams

Number of times by which 10^22 molecules of ozone is heavier than 10^22 molecules of oxygen= (48/60.23)/(32/60.23)

=>48/32 => 3/2 => 1.5 times.

Hence, 10^22 molecules of ozone will weigh more than 10^22 molecules of Oxygen gas, by 1.5 times